I use SRAM "exact-actuation" trigger shifters on three of my bikes. Once the derailleurs are dialed in, no hunting is required, like sometimes required for twist shifters, and the settings don't drift. Up and down shifts are fast. The only problem is "exact actuation" is available in only 10-speed shifters. Don't know how well 9-speed SRAM trigger shifters hold settings in combination with X-series derailleurs, and whether or not hunting is sometimes required, but I'd prefer them over twist shifters.