Start what with? I don't think either unit universally applies.
I'm one of those kids who started with a triangle, then moved onto a tambourine... I started with my mouse, if your already ****ing wit' a midi controller before 6 months of playing around in FL, or LMMS or something, then you've missed so much that you won't learn in Reason with a midi, it may sound stupid but the producers in my local area will agree with what I just said... Seriously, my mates had an MPC for ten years, and he's making similar beats to me, the fact I have 6 months of fooling around in LMMS on my resume makes me so much more experienced... No joke, I know a lot more than he knows, e.g. with filtering, and all the effects, and how to make the beat sound the way you want... Now I've upgraded to an MPK 25, and I've learnt a lot more on top, I'm progressing a lot quicker than a lot of producers I know who went straight with the big boys, and went all in with an MPC thinking their producing extraordinaires. In 18 months I plan on buying the latest Maschine, or if anythings better then, then I'll go get one of those new ones... I have a plan, I am keen to stick to it, I want to progress slowly, I don't produce as much as I like. Since the end of February, I only completed 100 beats... Instead of making beats I've been researching into sampling in my spare time as well... It has made a huge difference to what I create, if that's with a microphone, or with the pads on my MPK...
Basically, if you want to waste time and money going straight on an MPC, go ahead, but I'm sure those who have started out on mice, and have moved their way up will agree with me on this, and those with the controllers, and hardware in the first month they started producing will disagree with me, but whatever. I am glad I've taken my time, because just the difference of going from a shitty mouse, to a controller had made life easier, and it's a feeling you'd probably get from being broke, and living on the streets then working your way up to your own apartment, next I'm going for that big ass family house in the suburbs. THEN I'LL GO FOR THE MANSION WE CALL THE MPCs, AND ALL THE REST OF IT.
The fact the Maschine will have everything there, in the controller gives me motivation to make beats... I can't wait for the day when I'll be sitting there, chopping the sample with the Maschines knob, and duplicating everything without even looking at the computer screen.