Rye,
Given the choice from scratch, Revo is my preferred tuner, simply because I've had it on my old cars and I know them and their work very well.
As you know my new car came mapped already by Superchips, the Bluefin (now its been updated) is excellent - rapid & no jerking/laggy changes. It hadn't been updated since Jan '07 and the progress they'd obviously made in tailoring their maps was very evident. I'm not sure I could be bothered trying to split differences between the two, so therefore I would highly recommend both.
The only thing to consider is what you intend to do in the future? if you're just happy with a map then pick either... if you plan to mod the engine more, then Revo will be more adaptable to your needs.
Get some trials under your belt and pick which suits you best - they're both very reputable tuners and have dealers near you.