I have had a TMax in my 08 Dyna since August of 08. Had it installed by Zippers at Sturgis.
Yes, the security fob is recognized and works as usual.
Yes, the turn signals work just fine.
Yes, the bike runs a little cooler.
Yes, I can feel more bottom end.
Yes, it is more fun to ride.
Yes, it auto tunes and runs the same from sea level to 12,005 feet, the two extremes I have taken it to.
Try it, you'll like it. However, it is overkill if you are not going to do anything more than a stage I build.