I own the TRV-900 and think it is a great camcorder and for a mini DV cam is very good in low light. Although saying that mini DV cams are poor compared to old analogue cams at low light filming, but the TRV-900 is one of the better ones.
When the TRV-950 was released I was very interested in it and had a good look at one. IMHO Sony replaced quality on the new cam with gimmicks such as bluetooth etc which I see very little use for.
As for buying one - well it has been discontinued for a long while now, so if you do find one new you will be very lucky I think. I have just spent about an hour searching the internet for it and got nothing. Several sites point to
www.microwarehouse.co.uk with a price of just under £2000 (thats more than I paid for mine 3+ years ago on the high street), but when you go to the site they say no items found. I think you may need to go second hand if you do want the TRV900.
Sorry I can't be more help.
Mark.