I've had no problems with the RSX brifters I have and have had. What I like about them, over the Sora, is the lack of the thumb shifter, since I ride the drops and the Sora's aren't the greatest for folks who ride the drops.

My experience with RSX components is with a very smooth triple group. The FD/RD, and 48/40/26 crankset worked flawlessly with the 3x7 brifters. I've only seen RSX brake calipers with an 8-sp setup, and they were very similar to the 105 8-sp (dual pivot) calipers, only the finish wasn't quite as nice.