Consider the SHO as well, I think that's an excellent booster. It's basically just a buffer with the boost fully counter clockwise but if you turn the boost up a bit you just get a bit of extra clarity and sparkle which I find really appealing.
I see... I thing that the SHO works well por boost another pedals and adds high-end. I have listened a lot of good things about the RC, I am going to try to compare them...
One thing to consider is whether you're boosting a tube amp or not, I've found that using what many would consider to be a transparent booster makes my Fender Blues Junior sound muddy and too bass heavy, sometimes it's the treble boosters that give me a final sound that's closer to my original guitar tone.