Are you serious with PS3 having better voice chat quality?!?!?
I experience the exactly opposite...the only game I knew on PS3 is UC2, which has kind of acceptable voice chat and Resistance 2 being the best overall. But on Xbox360 voice chat quality is not only more consistent but IMO overall better - at least in my experience.
Here an example for you:
The biggest problem is when you want to meet up with people in a game and something unexpected happens.
If everything works ok, you meet in the lobby and can typically chat there...but if someone is missing due to what ever problem, and factoring in that he is probably new to online gaming - what next...where to meet, call by telephone is often the only option and is ultra lame IMO.
Getting back to XMB and meeting in the chat room, to talk - is ultra lame as well. If we had at least 1 to 1 chat, you could coordinate everything with a breeze...and it sucks that PSN does not support this!
Now talking about meeting not with one guy, but with a bunch of people gets frustrating very fast when something unexpected happens...how do you coordinate things when you cannot communicate?
If you are talking about playing online alone, which I do for instance in BF:BC2 - no problem at all, I just get online, right in to a game, and play...in such a case, there is indeed nothing missing...
The quality is better. There is no cap on PS3 games for the bitrate used in the audio codecs, and many times developers will spring for the higher quality (since they can). On the 360, currently, they are limited to the old voice chat codec that has been around since the original Xbox. There is absolutely no question that the quality of the voice chat is better.
The consistency of the user base using voice chat, or the lack of cross game voice chat, etc, is not a part of this.
As for the whole cross game chat, parties, etc. It's a comfort convenience. I participate in forums online, we set up times to play, we're there and we play. There's no absurd "one hour waiting period". That is self inflicted. NEVER will you encounter an experience where you are FORCED to wait for an hour. If you're waiting for other players that is YOUR fault, period. It's extremely easy to coordinate with friends, set up times, etc.
We start our games at a set time, if people show up late, they wait until we're finished, we're not going to wait for them.