You'll probably want the drummer version of the race ecm. I had the standard ebr race ecm when I had my d&d on and they did not get along very well. I have a spec ops on now and from the research I've done it sounds like the drummer version is the way to go for exhausts like the voodoo, spec ops, hawk, and drummer.
As far as more hp, my butt dyno says there is a noticable increase, throttle response is quicker, and fuel efficiency is better. I would still get some decel backfiring, but nothing too bad (but it wasn't bad for me with the stock ecm either). Overall I really like the results with the race ecm, just sucked how it wouldn't get along with the d&d...