I like it - what, specifically do you want to know? It does time based stuff very well, and the reverbs are reasonable, though not as nice as the PCM90/91 which has 2 reverb engines (as opposed to the 81 which has 1 reverb engine and 1 FX engine).
I wanted to add a good multi effects processor into my signal chain. Upon further research, it seems as though the PCM 91 is probably a better choice.
What about the Eventide Eclipse?
The PCM-91 is primarily a reverb processor, not a multieffects processor.
Another option would be to get both a Kurzweil Rumour and Mangler. Rumour for reverbs and Mangler for the multieffects stuff. That would cost less than either a PCM-91 or 81. Or, if you can afford it, a killer multieffects box is the Kurzweil KSP8.
You get a lot for your money though. The KSP8 is an 8 buss processor (any combination of mono or stereo busses), and you can chain effects on each buss up to the limit of the KSP8's processor. There are 16 "units" to play with. So it's like four multieffects processors in one box. If you price it out like that, each stereo buss is actually less expensive than the comparable boxes like the Lexicon PCM-91/81 or Eventide Eclipse. I know it's the total cost that gets you though!
I hate to sound like a broken record, but the Kurzweil Rumour has both reverbs and delays in it. You can't use them at the same time, however. It really is on a par with the Lexicon PCM-91 as far as quality. A different sound, but a good one.