Originally Posted by
vespasianus
I have found SRAM to shift a bit slower than Shimano. But nothing to really care about but I have found that Shimano's system works well.
the difference in shifting speed between Shimano and SRAM is down to Shimano using larger and more powerful motors. The larger battery enables this while maintaining reasonable battery life. The smaller SRAM batteries limit the size of the derailleur motors - Shimano-sized motors would kill those little batteries. The difference in signal transmission speed between a wired vs wireless system over a few feet is essentially non-existent.