Kev999
cryophonik
For your needs, I'd suggest a Studiologic SL-990...
He said he doesn't need weighted keys.
True, but, he didn't rule them out, either. He says he needs 88 keys, he says he's "not entirely sure how I would feel with semi weighted vs something else", and he says he doesn't "actually NEED something that plays better" than his synth action keys, but he doesn't say that weighted keys are out of the question. Most 88-key controllers are going to have weighted keys, but if the OP is not interested in them, he's free to ignore my advice.
Also, I just realized that I mistook the Keystation model that the OP is considering, and I was thinking of a different M-Audio Keystation. The model I had was the Keystation Pro 88, not the 88es. So, disregard my comment about the keyboard action - the Pro 88 had weighted keys, but a very low quality keybed IMO. I have no experience with the 88es. Sorry for all the confusion - just trying to help.