There are some forums where you can ask about it. I forgot where but I was reading em not too long ago.
The difference between the Phillips and the Sony from what I understand is just color. They use the same parts and everything inside. I think the Sony one has a special feature to let you transfer stuff to Sony VCRs or something like that.
I'm definately interested in getting perhaps the DirectV/Tivo combo. I want to build my PC first but soon...Sooon.
Also, there are hacks for things so you may wanna check around. For example, if you get the 30 hour one but it's one that comes with 2 hard drives then you're stuck. However, if you get one that is 30 hours and only a single drive or a 15 hour single drive then you can upgrade. And here's the best part. You can buy like a 60 gig drive and increase the space BIG TIME. I've heard some say they have 72 hours worth of recording capacity.
So that's also something to watch for. I don't know how to tell which have single's but I certainly want one.