That's not for me, since it's not a slider landscape keyboard with thumb-typing haptics.

I've used such devices in the form of the Psion 5 and Psion Netbook. Switching my touch typing between those and a fullsize keyboard crossed the streams in the muscle-memory in my brain. Blue smoke flowed out of my of ears and frazzling noises were audible... There was no way to keep the muscle memory seperate, for me.

A thumb keyboard trains a seperate part of my memory, and thus doesn't trigger associative cross-signaling.