If the OP buys Reason 6 right now or the very near future he'll get a free upgrade to 7. Even if the MIDI out addition isn't as useful the slice audio to REX should be a god send to anyone who never spent the $200 on Recycle over the years. (18+ at this point

).
On the MPK61, some people had issues on the 49/61 with a key on the last octave popping off, but I would guess that isn't going to happen on every one them. Although it was concerning to see it more than once.
The pads on MPK's are mounted wrong and really need to be on full level to be used. But you have the 1000 and would be better off maybe buying a $40 set of Fat Pads from MPCStuff.com rather than Fat Pads for the keyboard.
I have an MPD32 and the faders, knobs, buttons and presets are identical to an MPK, it's 78 total assignable MIDI controls and the Reason and Live bundled presets work well with out much additional mapping. (Mapping is quite easy, could be done on the unit or even easier in the software and saved as templates).