I just shot my new XD40SC for the first time and was also shooting my Tactical & Service mods, and there wasn't a lot of deffrence between the 4"& 5" guns but the SC had a little snap to it. The Tactical in 40S&W is a pussycat to shoot compared to the SC, so I would say stick with the 40S&W, just so they both eat the same thing at dinner time, and the tactical mags will also work in the SC ( just be carefull not to push them in too far or they will breack off your ejector).