Been there pal. I've fit 3 RS's on the same bridge, each time improving the fit. On the latest attempt I sanded my bridge very carefully in an effort to get the surface planes of the wing and the leg of the bridge as close to parallel as possible.
The first time around (planes not parallel, worst fit), I liked it with the "R" symbol facing the table, not the strings. Sounds like you prefer it that way too. It was nice and velvety and warm and kinda dark sounding. The second and third time around, as I improved the fit, I decided that I preferred the tone with the "R" symbol up facing the strings. It had just as much booty but with better articulation.
This might be a crude oversimplication, but IME facing the table gives you more table / body, and facing the strings gives you more string articulation and bounce or boing. Kinda obvious, I know. IME, with the "R" symbol facing the strings, I still get plenty of body though. The whole equation might depend too as you know on how dark your bass sounds on its own, choice of strings, amp, etc.
I kind of concluded that when the bridge wing slot was not parallel, I got the best sound with the orientation that gave me the most surface area contact between the bridge and the "R" symbol or p/u "hot spot." At first, that was down - but then, as I worked on improving the fit, it worked better up, as designed.
