If you're not sure you can download the manuals in ∗.pdf format and read abiut the product before you buy..
http://www.m-audio.com/products/midiman/keystations.phphttp://www.m-audio.com/products/evolution/index.phpMakes interesting reading..
In my past job I've used all these USB controllers and they're all good for the money..
I still think the Oxygene8 is a good size.. In fact I've started to convince myself to acquire one instead of getting really heavey Motif out every time I want to do some sequencing in SONAR..
Regards
Kevan