you can point a lot of criticisms at MC303s, but i tell you this...

i used 2 for years & years. ive done live sets with only 2 mcs & wrecked clubs.. and they DO NOT CRASH.... unlike laptops ;)

the midi timing is bang on & the programming is a doddle to knockup drumloops.

i have also used them on the fourth channel over 3 dex.

also great as a drumachine. imo