I have the limited edition red version of the MPK 49 and I love it. The keys aren't weighted, but they have a great response and don't feel cheap or fragile like a lot of midi keyboards. The pads are also really responsive, and the built in sequencer and arpeggiator are great for quick inspiration.
I use it a lot, the build quality is amazing (except for the pads, but I don't use them), the arpeggiator is absolute madness when put on "1/32T", the knobs and faders really come in handy. Can be used for live and studio, even if it's a big big for a small studio. 10/10, would recommand.