PlanetZ forums - scopeusers.com

I'd recommend the Linplug RMIV over battery, having had experience with both. Linplug doesn't have teh 'super easy' graphical envelopes but you can still envelope, and there are quite a few interesting features in there in addition to just layering samples...

http://www.linplug.com/Products/RM_IV/rm_iv.htm

looks good and is even cheaper.
It's at a disadvantage however in loading Akai cd's.