I've got a pretty big Akai library. A LOT of people got good Akai libraries, and a lot of people are selling good Akai libraries. Other than a small Roland representation, and a bit of Emu, the large majority of all sampling done until recently, when Giga and Soundfont took off (and most of those are too big to load practically into an arranger) was done in the Akai format. Which also had the advantage of a mere 32MB of RAM, so the samples are well optimized to take up as little RAM as possible and still sound great (just what an arranger needs!).

Simple fact of the matter is, if you want RAM efficient sampled instruments, you HAVE to have Akai import. Otherwise, you have so little quality choice, it's hardly worth the bother...