PQ wise go for the VT30 definitely. I was actually considering getting one already before the years end.
However, that green blob issue is really scaring me away from purchasing one. I've also read some reports in other forums that there are some users who initially had no green blob issue and then it suddenly reared its ugly face after a few months.
As of now, I have decided to hold out for 2012's ST50 model. Unless, I can find a good deal for an ST30 which is pretty hard to find now.