Your father is unaware of the history of Sony/Minolta, the third-party photography markets, and the entire concept of obsolescence as it deals with 2009-2010 era professional/semi-pro photography gear.
I'm sure he's a great guy, but he also appears to be the kind of consumer that aggravates me. So he read an ad in Time magazine, and now he's an expert in photographic equipment? Really? That method of thinking is almost alien to me. My college education of deep research (ancient history, astronomical physics, etc) was followed by a career of deep research (journalism, writing). How can anybody decide on something with zero research? Or worse, read a marketing pamphlet that lacks independent information, and then form an opinion based on that bias.
Since the source was Time magazine, at best he saw a press release (biased info) or regurgitated press release (reduced bias, but still biased). Maybe a review, which could be biased by the review process used -- some pubs force reviewers to limit negative commentary, and force that positive comments be made, in order to not offend current/potential advertisers. (Not sure what Time is like these days). Unless he's a photographer, he would be unable to discern the quality comments from the marketing malarkey.
Let me touch on a few points...
The D7000 is technically a consumer camera, but it's really hard to lump it with the cheaper class bodies (D40x, D60, D3000, etc). The D100, D200 and D300 were technically consumer cameras, but were more like mini versions of the pro bodies available at the time. The D100 was chasing on the tails of the D1H/D1x, while the D200 was a "mini-me" version of the D2x. The D300 improved on the D200, not really a mini D3, D3x or D3s. The D700 is the mini version of the D3, and the D7000 is sort of a mix between D300 and D3s features, but with D3/D3s exposure quality.
I bought a D200 because it was more or less the same as the D2x. No such "mini D3s" existed, so I had to buy the real thing. In terms of a backup body, I currently use the D200, but that new D7000 is very tempting -- VERY tempting. It's a hard choice between a D700 and D7000, should I need to purchase a new backup body in the next 6-12 months.
I didn't pay $5200 for my Nikon D3s because I'm rich or because I like expensive toys. I needed the quality found ONLY in that camera. I was not going to compromise my art, or limit my skills, by trying to save a few dollars. As an artist, there's no way to grow if you limit yourself. For me, a D3s poses no limits. For you, a D7000 poses no limits. (Heck, for that matter, D7000 poses few limits on me, either.)
Is the Sony A55 as good as the D7000? No, not really. It does do some things almost as good as good as the Nikon gear -- but the overall package is weaker. I refer to not just a feature on the body, or a certain ISO performance, but the entire photography experience as limited by Sony or Nikon.
Sony does not make bad cameras. Sony makes
interesting cameras. If you have a certain niche need, the Sony line of equipment can most certainly fill it. There's a reason you only find Canon and Nikon bodies at press events, 35mm format studios, sports, etc -- and it's not brand loyalty or false perception that those are the only brands that can be used. It's about the gear performing the tasks we need.
Sony bought out Minolta back in 2006, to enter the consumer DSLR camera market.
Minolta was an old camera company (1933 according to Wikipedia) that was very good at making cameras during the middle of last century. They made highly respected and rugged metal bodies, and introduced us to the bayonet mount, metal bladed shutters and program modes for SLRs.
But by the time the 1990s hit, Minolta gear was mostly low-end consumer fodder. The idea that a "high end" Minolta Maxxum could compete with even a N8008s, F4s or F5 from Nikon -- or a Canon EOS of similar pro/semi-pro status -- was really a joke. The best camera that Minolta had to offer was about on par with the N90s -- Nikon's professional-quality "consumer" camera of the day (not too dissimilar from the class of camera a D7000 falls in). It's been so many years that I can't even remember all the problems posed by the bodies. Some of it was gimmicky features, some of it was bad/slow AF. I remember being at a newspaper at that time where many of us photographers would trade jabs and insults -- usually in good fun -- when in the darkroom together. A popular insult was "Did you shoot that with a Minolta?" (Or a Polaroid, if it really was a bad shot.)
The biggest problem with Minolta has always been their crap lenses -- a problem that persists to this day. You're forced to seek third-party lenses, which may or may not exist. Nikon and Canon really get all the lens choices, because that's where the market is. Nikon and Canon make their own, and then companies like Sigma, Tokina and Tamron offers some too. (Note that quality can vary quite a bit on those third-party lenses. One Sigma can be optically near-perfect, while another one struggles to simply be focused.) It was also my observation that Sony/Minolta (A-mount) lenses were unjustifiably more expensive.
There's a perfect example of this up on dpreview.com right now. A new comparison page at dpreview.com/reviews/canoneos60d/page17.asp exemplifies the optical discord between camera systems:
nikonvsminolta55.jpg
That Minolta shot is soft, regardless of ISO, regardless of location on that large test image. The Nikon is just as clean noise-wise (and with NR OFF!), but with far more detail and superior color fidelity. Look at the fuzz, the shadows, the gradation of light and color. The Sony is crap. The Canon is better, but the Nikon is clearly ahead here. A D3s at ISO 25600 has the same shadow/detail/color quality as the Sony A55 at ISO 200! That's awful -- for the Sony, that is. (Note that the grain of the D3s image gives false appearance of detail. The real detail was lost, and would be pretty close to the A55@200 with grain removed.)
Can you imagine spending a lot of time painting, paying close attention to brush stroke detail, shadows, black/white purity, color blending, etc --- only to have the camera butcher everything you just did? That's no good.
I owned a Minolta in the 1990s -- in addition to a Nikon and a Canon. The Minolta was given away to a family member, to use in school, because it was simply ill fit for serious work as I started to shoot more and more serious work. The only way I'd buy a Sony is if Nikon and Canon both went out of business.
Minolta cameras (and the Sony continuation thereof) have also had a bad habit of burying important controls in menus and sub-buttons. That's my primary source of discontent with Canon systems -- quit burying the controls! Nikon puts everything in easy, quick reach that I could operate blindfolded. (This is the same preference held by Ken Rockwell, and is one of his listed primary reasons for using Nikon gear.) I have work to do -- I can't sit and twiddle buttons and navigate menus while I'm trying to shoot.
Sony bodies simply do not have the range of accessories, quality of lenses, and overall quality experience like Canon and Nikon do. Had you asked about a DSLR body a year or two ago, I'd have listed a few Canon systems as being something to consider (D40, D50). But right now, The D7000 is the way to go, as Nikon is exploding in the camera world, and Canon can't keep up. It's been many years since I saw so many Nikon lenses poking out of press areas and being used in studios -- all of it gear from 2008-2010.
Now is a great time to buy, and that D7000 should be a great setup to own. I hope you're able to get it.
As far as that camera being obsolete? That doesn't even make any sense. That sounds like parroting of propaganda for the non-flip mirror system. If anything, I would imagine that having "normal" mirrors will not ever change for professional gear -- at least not in our lifetime.
Beyond that, all cameras become obsolete -- whether the film format plays out, when the company (and its proprietary lens/system) goes under, or the digital guts are low quality compared to the latest hardware. Nikon is a camera company that's doing well, and has been at this for 50+ years. Sony has not even been in this market for 5 years. Who do you trust more to still be here in 10 more? I know my answer!
The only way I'd use a Sony is if all my Nikons were broken and unfixable, if I could not borrow my buddy's Canons, and the Sony was free.
I'm maybe coming across a bit harsh here, but I want it to be said in no uncertain terms that the D7000 is a better choice for many reasons. This isn't like ketchup, where you can pick between Heinz and Hunts, or even a store brand name, and it all tastes the same. There are consequences of picking 35mm gear outside of the Nikon/Canon norms.
