Hi there, welcome, glad you posted.
Media Temple was actually supposed to be ranked 3rd, below
LiquidWeb. Oops. I updated the list a few days ago, got sidetracked, and didn't completely finish it seems. I need to do that tonight!
All of these hosts are very close when it comes to rankings.
(Very soon, hopefully in the next month or two, we'll be publishing all of our host ranking criteria. Most people will see that it's NOT an easy process! We rank based on a quite a few things that most people never even consider, but are very important. We don't rank on superficial BS like almost all reviews online tend to do. We're a lot like Consumer Reports, but even more transparent.)
The biggest difference is
1. the hardware
2. the speed and effective of support ... assuming it's even needed (most times, after initial migration/setup, it's not)
Most Xen hosts are going to rank better than Virtuozzo or OpenVZ hosts. MT was just an exception, because of the hardware and support quality, as well as preventing node abuse. Many Virtuozzo/OpenVZ hosts won't even rank because that virtualization style allows too much CPU abuse.
Media Temple just had excellent hardware and support, even more than the others (
WiredTree, Futurehosting,
Knownhost, etc). There's actually a chance that those other hosts would improve in rank if they ever switched to Xen, KVM, VMware or Hyper-V.
Like I said, it's close, especially for Futurehosting and
Knownhost. (Not so much
WiredTree.)