Sorry John but I disagree. I owned a KMA briefly, and IMO it was a failed opportunity. I'm posting here to let Korg and the other manufacturers that there still is a market for an ultra-portable arranger. But the KMA wasn't it and here's why...

I'm really trying to learn playing by sight, without looking down at the keys. I don't practice enough as it is. So if I'm going to develop that "muscle memory," I need to stick with full-size keys. Having something that I can take with me to practice is great, but I'm not about to confuse myself by messing with this.

YES, the KMA could be perceived as a fairly capable MODULE. However, in that case (or any case) they should have ditched those tinny on-board speakers. Poor bass response IMO. And with the abundance of portable speakers like the JBL Charge, UE Boom, etc., on-board speakers needlessly add size and weight. If you're going to practice in bed or on the train, you'll probably use earphones anyway. Oh, that's right... you CAN'T practice on the train because the KMA doesn't take batteries! Sure, you could cobble something together with velcro and a big power bank, but why...? Ditching the speakers would allow pitch/mod wheels to be ABOVE the keybed. Then, they could have put a full-size keybed in a similarly-sized package. Bottom line, I give the engineers a C-minus at best. Korg should have based their MicroArranger on the Kross 2 package which is only an inch wider, it takes batteries for truly portable use, and weighs a pound less.

If length must be kept to an absolute minimum, consider the following: Deane (Hammer) claimed to be able to play a full set with his Ketron SD40 module and a four-octave controller. Personally I don't think four octaves is enough. But I often play in the Key of C, and a 4 1/2 octave controller beginning on F or G would allow me to play most of my repertoire, and could potentially be 32" wide with full-sized keys.

Anyone interested in a KMA should probably check out the Casio CT-400 which is a similar size and weight with full size keys (admittedly a crummy action.) If you really need sequencing or user style creation, you could get a Casio WK or CT-X for your studio to complement the portable CT-400, for about the same total cash outlay. My $.02.