If I may suggest something, I know most of you play with headsets activated, but I don't. Mainly because I got none myself (I rather enjoy PS3 sound on my stereo which also makes GT5 sound a
little better) and, because of whatever reason, even when I set voice chat to highest quality possible in my lobbies, all I get when people are talking is unidentifical pieces of words and sentences. It's like lagging; I hear them for a small moment (a very small one, 1 or 2 words), than it's interrupted, continuing a few seconds later again just to interrupted again. I have the same when I join any random open lobbies where I don't know what quality voice chat is set too, so I usually just end up muting the people anyway.
When I'm in a private lobby though, organising a photoshooting or cruise (yeah, basically I do anything in GT5 but racing

) with headsets activated is no problem at all, I can understand what the others say if they have a headset. Also, it seems to be fine with all connections to do 35 minutes-photoshootings (= races so we can save the replays) with race quality on very high and voice chat on high. With 8 people in from 7 different countries, if I remember correct all from the EU, but still. I had more experiences where voice chatting in my private room was no problem as well. Can't tell about other's lounges though.
I have to say, although I have a wireless connection on my PS3 which as we all know is definitely not the best way to go online with it I rarely have problems with lag or lost connections. Even more, since a few weeks, the game online is actually working A LOT BETTER for me. Before it kept freezing when I tried to join or create a room, 8/10 cases, it was so annoying it actually kept me from playing online several evenings. I thought it was fault of my connection, but when I did a quick speed test on my PS3 I always got a download speed like 9 MB/s (with cable it's 32MB/s on PC and ~20MB/s on PS3) and a signal usually 70% strong, give or add a few percent, it keeps changing. But than, from one day to another, some PSN friend dropped me a message and told me the never-ending-loading balk glitch was fixed (that's what we called it lol, we both had it, actually all of my PSN friends I asked) and I tried... and it was true! I joined rooms about 25 times since that in the past 2 weeks and it always finished loading.
I suppose PD knew about that bug (server overload?) and fixed it now, maybe also because of the start of GT Academy, to make sure less problems happen to the demo players... I didn't change anything about the internet connection, and test results were the same as before. No temporary data cleaning since several months as well. Plus, once I was inside a lobby, I could stay there a whole 24 hours without leaving or losing connection ONCE (yes, I actually tested that... might be something I'll add to the "You know you already played too much GT5 when..." thread

), though it was a cruise room, so there only was free drive, but there always had been at least 5, usually 8+ people inside, max was 14. I kept active about 90%of the time, it became a bit hard in the end so I slept the last 4 hours just for the achievement in my head of having stayed in a lobby for more than a whole day. When I woke up in the morning I looked at my clock and I was actually a full 24 hours and 32 minutes in there. That would be quite good even for a wired connection, wouldn't it?
Anyway, this is getting too long lol. Let's make it short, my experience is that even with a wireless connection that is not exactly strong you can play without problems and anyone can join, as long as you keep the voice chat off.
I'm such a nerd, typed all this on my PS3 with my USB keyboard because my PC is off, though the cursor/button lagging on here is so terrible delaying it would've been faster to power up the PC first and type it there.

Sorry for any typing mistakes, noticed I left out some words but navigating the cursor on this is a pain in the arse.