As someone who went from the 950 to a similar product to the 997, I would say the room correction is a pretty worthwhile improvement for movie soundtracks.

I defeat it for music as I try and get as much processing out of the chain as possible for that, and my room is reasonably symmetrical in its setup if not so perfect acoustically otherwise.

But I went from the 950 to my new pre/pro, and the current generation of sound codecs made one level of difference (I am using a PS3 BTW). When I began using the Audyssey in my unit, though, the steering and channel separation improved an additional step, especially for off center seats. I would expect the Trinnov processing would do at least the same.

I don't know if that is worth the price difference between a 990 and a 997, but it is a point to consider.