That Akai is really a repeat machine with small keys which would annoy me.
I do think that the Yamaha drum machine is great because you can integrate that with the likes of Cubase and create drum tracks which could be great alternatives in styles or if you are mult-layering. Great also for a tight space with a band. Instant drums after the learn process.
All songs need that little difference that makes them individual.The Yamaha can also play sounds and you have access to multipads then.
If you go for a small keyboard, make sure you get full sized keys, unless you have ultra slim fingers. Small keys are just awful IMO.
Ok you can program drums on the Genos , but the way the pads are layed out it it is better for finger drumming.
It is also portable :)and you could program drums to a laptop anywhere or just the machine itself.
I think this device will be a winner