My opinion may change with the 3.0 upgrade, however currently I very much feel like the PSN is an addition to the PS3, while XBOX Live, is integral to the 360 experience. Here are a few things I currently consider lacking on the PSN:
1) I have a USB headset...and I can't send a voice message to my friends... what?
2) No notification that friends are on-line...I was waiting for a buddy on-line, while the whole time he WAS, I just wasn't notified. If I hadn't gone to his list to send him a voice, text, I wouldn't have known.
3) No notification of new mail messages?
4) Cross game chat and party systems are known differences.
That being said, I don't HATE the PSN...hell it's free, how could I hate it? I wouldn't "pay" for it though, so I'm glad I can enjoy what it does have to offer. IMO, it is NOT that similar to Live though, at least not yet.
