To see the quality of a Card's digitizer, ... which is most importand, you can connect a Stand Alone DVD Player via S-Video cable to your capture card.
Use for testing a very good Quality DVD (no noise, excelent mastering!) and capture some minutes using your settings. But be careful ... the input signal will be interlaced and therefore you have to choose the max possible high CBR when capturing to mpeg2, and also to see its clear potential!
And also do another test by capturing the same scene but using a mjpg codec like PicVideo (set to 6-7mb/s- if possible- or a very high quality in Picvideo settings) or better : Choose the Lossless HuffYUV codec.
This for beginning gives you a good impression how your digitzer works.
Cause it won't be that manipulated by "broadcast"-noise, ... received when capturing a TV signal ... and every brodcast comes with his "own" noise so its very difficult to see the digitizers capabilities when testing.
Maybe after this workout we could see some Pics in here?
And if the Quality by using the DVD input as reference comes out very good, you don't need to chnage to a PVR 250 ... so everythin in your case depends on the encoding- codec engine.... (well that's my opinion ... cause you can spend those 150 Euros or Dollars on other useful things).
PS: I had a PVR 250 for testing .... it delivers a very good quality ...
But I still stay with my Pinnacle/Miro DC30 using Win2000 WDM Driver which also gives me an excellent quality so I don't have to spend again money incl. no real quality benefit... as I figured out by doing the comparison as mentioned above .... cause I had to send the PVR 250 back.
But if someone would have to choose his first Capture Card, ... shurely I recommend the PVR 250 as I already said