Good drum machine. The sounds and samples are very realistic. The bass sounds are quite good as well. Triggering patterns on the DR-3 is very similiar to an arranger keyboard. There are dedicated fill, intro, ending, and main buttons for each pattern.
Velocity is good on the pads. My only gripe there is that it would have been nice to have larger pads. Plus for some reason Roland/Boss added a slight curve to the pads. They should be flat, and those of us who are used to flat pads may take some time getting used to the DR-3.
It allows you to edit your own kits, has some built in effects with user effects as well. The backlit screen is a plus. It responds well with midi.
Overall not a bad drum machine. The problem is that Boss priced it too high. It still currently sells for $195.00 new (without the adapter). Zoom released a new model that has more features than the DR-3 and it only sells for $179.00