I went the remanufactured route with my motor at 108,000 miles, not so much because it was tired but I wanted to go with the black and chrome finish, since I was redoing the whole bike after a little crash. The new motor is a little more oil tight, no base gasket leaks. It did burn oil like crazy though, found out 2 valve guide seals were installed wrong. Remember if you send in a modified motor you get a stock one back, so take it out the cams and things before you send it out.
If your just looking for more power, the standard mods, as well as having heads ported and polished might be all you need.
2009 Suzuki V Strom 650