I got the phone as a xmas gift for my fiancee and I've just recently rooted and put a rom on it. No flash is always a downside to me, but I have a G1 right now so i'm used to it (waiting for my upgrade too). I have to say even without overclocking and all that, it's a pretty sweet phone for the price. I've been able to overclock it from 600 to 768 stable. Some can go higher, some bug out when you do.
As far as games, I can play pocket legends and angry birds with no lag. I haven't really tried too many other games, but I will if you have any suggestions.
While I've only seen about 2 roms specifically made for the optimus t, most of the optimus one roms work perfectly fine.There is alil bit of growing support for the optimus t now. Wifi calling seems to be exclusive to the optimus t right now, which can be a plus if you're in an area with crappy signal like me.
Overall, I think it's a great phone if you don't wanna spend much money. The only problem I've come across is a small issue with the touch screen acting funny (acts like you're multi touching or tapping somewhere else on the screen when you're not) which is actually being work on now by a new kernel.