I produce some electronica tracks (Orbital style) and the main benefit I see is not having to put up with computer crashes, software issues, etc (and the temptation of surfing all day!). Effects in the MPC are not the best mind you but I work with a midi controller keyboard, hardware multitracker (with onboard effects), multitimbral synth, sound module and my MPC with pretty good results in my opinion.
Having said that, if I had the money, time and the space I would probably give a computer based DAW a go.
Have you thought about an korg electribe?