Edirol is fine in my opinion. Of course, gpo is better, but the engine used is much, much newer than edirols.....you really cannot compare the two. But keep in mind that it was used throughout the 90's on tv shows like mcgiver, ect, so the sounds aren't wack by any means. Plus the install is small, doesn't hog resources, and has an easier interface to work with than any other vst's that have been mentioned in this thread. Never liked reason so I can't comment on nexus. East West collection is good, but GPO has a better value.....why waste all that space on samples?
Just my two cents-