Advice on keyboard controllers

I'm looking for a new keyboard for the production side of things. I'm on the simple MPK mini right now and I have just overgrown the limitations it has.

What I am looking at right now is something along the lines of the MPK 49 or 25; a controller with pads (hopefully good ones), and some good keys (I'd like to get 49, but 25 could do; maybe with aftertouch and some weight to them).

Other than the MPK series, I am not very knowledgeable in this area and any suggestions on what to get would be great. Price range is anything below $500.

Axiom Pro

Any info on pros/cons compared to the MPK?

edit: moreso in regards to its use in conjunction with Ableton

what do u find limitting about the mpk? i used to like using a fullsize roland jv90 as a controller keyboard. you need aftertouch etc?

It's the insensitivity & size of the keys / pads, the baby small knobs and the lack of octaves. I'm no pro producer yet, but I feel ready to step up into a controller keyboard I can grow into.

edit: I am talking about the MPK mini, just to be sure.