I don't know anything about the DOD but I've got a DD5 and it works pretty good for me. I basically use it as a bit of delay when I'm playing lead. The only downside is that about half of the features on the BOSS though are useless if you haven't got a stereo amp setup.
If you've got the money go for the DD5, BOSS stomp boxes are virtually indestructible!
Lastly, I'd suggest thinking about getting a power supply with it too... it goes through batteries pretty damn quick!!
