I've been using Pristine Space for reverb and I'm considering the jump to one of the higher-priced packages, mainly because they have IR's of great halls.
I've demo'ed IR-1 and it's fine, but the number of impulses is limited with the demo. It seems like Altiverb has much more in the way of instrument positioning capability but there's no demo, so I can't really tell.
So, how do the IR libraries compare between Altiverb and IR-1? I can't tell how deeply sampled the IR-1 library is - does it have multiple stage locations and mic locations? It seems like Altiverb has many more stage/mic combinations and a better interface for setting that up.
Here's another question: do you really need those IR's? I get a decent feeling of depth and breadth using just stereo width and three IR's (left, center, right) in PS. But it's not perfect...
Thanks,
rgames