Keep in mind that if something goes wrong you'll probably never get it fixed. TONS of proprietary IC's and circuitry. Also, it may be tricky finding RAM to expand the memory. If you're used to dealing with software samplers (like I am nowadays) going back to the old button/menu interface method. Also don't forget the 16 voice polyphony seems fairly skimpy these days.
Definately think about getting an old computer and some sound design software that interfaces with the EIII if you can.
I'd say that unless you are looking for a *VINTAGE* (or specifically hardware) sampler that maybe you'd be better off with software. However, if you want an older sampler (or hardware sampler) I would say that the EIII is the best, along with the Prophet 3000 (almost impossible to find).