Nice choice on the ROO and B&R, I've been thinking about picking up a rep of both myself. The SSD just seems a tad smaller in diameter. The crystal is different, I can't find the right words but let's just say I bought it and sold it 2 days later as it just didn't do anything for me. From pictures though i thought it would be perfect but in practice, no. The Sub/SD bracelets also, while true to the gen, feel cheap to me. My favorite rep I own is my Rolex GMT IIc, but it's the newer style bracelet and clasp(heavier) and also slightly larger in diameter than the SD.
The DRSD is very nice and IMO much better than the SD. Inserts can be bleached easily, vintage pearls are cheap, etc... If you're a tad hesitant there are many modders around who know what they're doing as well. Plus it's something a bit different than your everyday, dime a dozen, Sub or SD. Just my 2 cents...