On my 2010 StreetGlide I put the screamin eagle heavy breather, Vance and Hines hi output slip on and had the $150 hd stage one download. The bike ran and sounded great! If you only plan to do the ac and slip on the download IMO is the best way to go. Many of us have run with this set up for many trouble free miles and are very happy. If you plan to do motor work anytime soon then a tuner would be a better option as the download is for ac / slip ons set up.
Good luck with you choice.
T
I agree completely. Only variables from my choices were the SE Stage 1 & SuperTrapp (Nightstick) 2:1 slip-on. A simple re-map and the bike runs fantastic. Absolutely no need for a tuner or dyno.