Well I did it. 2011 SE Street Glide in black... Nice Bike. I have two must fixes. One: on my sore ass after 75 miles. Two: Exhaust Any tips Fullsac? 
Fullsac is hard to beat, particularly if you like the look of the stock cans, which I do. Looks stock, sounds and performs better, especially if you get the X pipe header to go with the cores, and TTS to reflash the ECM. It's a good, easy route to go, IMO. I put it on my bike with the 2" cores, and I'm very happy with the results thus far. It's an excellent product, with no fitment problems, and excellent build quality. Uses the stock heat shields. It'll also get rid of the Cat in the stock header, which is a source of a great deal of heat.
Seats? If your a$$ is hurting after just 75 miles, I'd look at a more permanent solution to the problem...as in a different seat. So far, I'm happy with the seat on my 2011 SERGU, but it's got a different seat than the SESG. If I were buying a seat today, I'd get a Corbin through hd-dude (Jim) here on the site...his shop's name is Metal Dragon. He can make sure you get a good fit from Corbin, and he is a member here, plus his customer service is second to none. He can also fix you up on the Fullsac system, with a discount. But, not everyone likes a Corbin...they are firm, but once broken in, 500 mile days were no issue for me on my '06 SEUC. I also had one on my '05 Ducati MTS, which had a 1x12 board for a stock seat that would kill you after 30 miles. A lot of people like Mustang, C&C...the list can go on for quite a while. I've heard a lot of folks say they like the Airhawk mentioned above, but it sits on top of the seat, so if you have a short inseam it's going to make that worse, plus it doesn't look the best in the world...it's a function over form item.