Pm, I've got both of the most popular tuners for both my Hemi vehicles and, as I said, the DS is a little better for economy. I never use the SC tuner on my Magnum anymore, but do change back and forth on the Jeep. I had been running the SC for quite awhile, solely because of the cool Trans. App. that is an option with it. I do that mostly because of the lousy stock shift schedules and torque management setup for the 545RFE. The DS now offers limited (1st, 2nd, and 3rd only) so it is a little better now, in that regard. The Maggie has a NAG1 tranny with full autostick, and is 1000 times better than the Jeep, IMO.
Other differences, if you're thinking of picking one or the other up are, the SC has some adjustments that can be manipulated for the off-roaders, and the DS allows you to update to the latest CALID flash files (about $100-150 to have done at the dealer) for the PCM/TCM, and gives you the ability to have custom tunes made. This seems to be mostly for the high performance engines, but some have said it works good for mildly modified engines too. Even with my mods., I've never invested in one (~$200-300, I understand), and am happy with modifying the canned tunes. In addition to some of the tuning mods. also incorporated in the SC tuner, the DS tuner allows you to adjust WOT fuel mixture and timing, which is helpful if you do a little racing. Hope this helps a little for you.
06 GCO, Dk Khaki, QDII, Flshing Hi 3rd Bk Lt, MDS "ON" Lt, Airtab Vortex Gens, Debadged, Fumoto Drain Valve, BT Catch Can, Chopped EGR Tube, SRT8 CAI, K&N Filter, Sonnax Trans Line Press Booster, SC Tuner W/Adv Trans Tune App, DS Tuner, Cust tubular hdrs w/3 in Magnaflow/Xlerator AP Exh Sys, Bilsteins, SRT Springs/Sways, Cust Eng Cvr, SRT8 frt/rear bumpers, FRI Sidewinder Cam/6.1 valvetrain, SLP 25% UD Pulley, BBK true 90mm T-Body, SOS Ign Coils w/.060 spark plug gaps, SRT Reps with 265/45&295/40X20's.