FWIW- I have used SRAM for a few years now (only the lowly Apex) and have logged a few thousand miles. It has been working great. I have no complaints so far with shifting or reliability. If I were to upgrade, I would have no problem buying SRAM. Here is a good video about the differences to consider:
Art's Cyclery Blog » SRAM Road Components ? Where to Spend Your Money
Last edited by etw; 11-02-15 at 05:06 PM.