Many but not all bikes will benefit with a indexed shifter with a trim position. Depending on a few things like gearing/bike geometry/size you may not need trim capabilities. But for the masses it should be standard procedure. On my Sram bikes the front derailleur doesn't need a trim position on the big chainring but does need a trim position on the inner chainring. On my Shimano and Campagnolo equipped bikes I really like having a in-line adjuster on bikes that do not have them mounted on the frame. Makes my job much easier to get the shifting perfect and this help make my equipment last longer.