I have made extensive listening tests when I was up to get some great reverb machines. I was used to the 480 very much because this machine was basically in any studio I worked. During one month I demoed a 480, a 960, a TC6000 and a Sony DRE777.
As already have been said, the 480 and the 960 are totally different beasts. In my opignion the 960 clearly is a big step foreward to the 480, and I can use it on nearly everything to get a great reverb sound, be it small chambers or rooms, or bright and magic vocal plates. I mainly work on stereo jazz projects, so I absolutoy likes the fact, that with the 960 I get 4 true stereo reverbs. On the other hand I think that the presets on the 960 are not that great, I have to spend quite some time to get it right, but if it is right then it definitly is great.
The 480 on the other hand has something magic. It will sound great with much less editing on the parameters. I have to admitt that I still would prefear the 480 on vocal or solo sounds in some situations. But finally the 960 still wins imo.
After the month of testing all those machines I finally got the 960, aswell as the TC 6000 (which is totally different than the LEX Machines, but also great) and I got two of those lovely Sony DRE777 which I also liked very much. I might still get a 480 later, but I really think it is not so important when a 960 is here. You could never get the sound of a 960 on the 480, but vice versa it is possible with some tweaking and additional processing.
Last but not least I think that a PCM 80 or PCM 90 (both I used often some time ago) are not at all in the leage of a 480, 960 or TC6000, really not even close.
My 2 Cts.
Daniel
www.ideeundklang.com