The previous models are still excellent optics, in some ways I prefer the trinovids to the ultravids...
One of the the big 'improvements' of the ultravids is the lighter weight, personally I find that in side by side tests they do deliver a slightly brighter and sharper image. I currently use the 7x42 ultravids and have been very impressed with them, lovely wide field of view and excellent in poor light conditions. If you are looking at 42mm bins then I think the ultravids are worth the extra money, though make sure you try the pair you are buying, the focus wheel can be an issue on ultravids.
However if you are looking for 32mm bins then I am not so convince by the ultravids, I find them too small for my hands. The larger ultravids feel great in the hand, but I cannot hold the small ones comfortably. The trinovid 8x32 on the other hand has the best 'in the hand' feel of any binocular I've ever used. Best advice (as always) is to try them for yourself.