Since you have the 4000 already and you just want something for portable reasons, then I say go for it yo!!!1

Plus you can load everything up to the 4000 that you work out in the 500....Just be fair warned, I bought the 500 thinking it was gonna get a ton of use and in the end I sold it because I don't really make tracks away from the lab. It did come in handy in a few situations( i.e waiting all night for the launch of the Wii, at a friends houses...etc) but it was more of a novelty item than anything. I don't travel much so
for me the mpc 500 was something I got real excited about at first but it really wasn't something I could justify having. This unit is more for(A) someone that spends long periods of time away from the lab but still wants to work on tracks or (B) someone who wants to use the mpc in the lab but can't afford the larger mpc's. Don't get me wrong the little 500 is nice but you, coming from the 4000 may find the work flow a little fustrating and at times limiting.
