I have a 16 SGS as well, just put these same pipes on a week ago. I didn't do the headers or intake, just the slip-ons, and did not remap/tune the bike. So far the ECM has done a great job of adjusting to the new slip-ons. I took the money I was going to spend on a VO2 intake and FP3 tuner, and instead ordered a Mustang seat...
For me my priorities are safety, then comfort, then performance. The pipes and LED headlight and signals/brakes were done first on my bike because I believe they make me safer (I can't tell you how many people nearly merged into me when I had the stock slip-ons on the bike - around these parts, if people don't hear you, they don't see you). The seat is needed to make longer trips more comfortable. Once I get some more cash scraped together, I'll get to the upgrading performance (finishing my stage 1 upgrade with an intake and tuner - and maybe headers!).