As far as I know on here, Lamont and I are the only ones with M109's on here. I have an 07 LE and I wont ever get rid of mine. This has been my first bike also, so I might be a little biased . I'll list some of the issues that I have seen on the M109 board.
1. Fuel rail recall, 06 & 07 models
2. Loose rear brake rotor, 06 & 07 models
3. transmission: 2nd gear shift fork; this seems to be sporatic and a indicator how the 9 has been riden by the owner.
4. Clutch cable: not enough slack in line & routed incorrectly. Easy fix, route outside motor mounts and leave "2 quaters" of slack in cable.
5. Suzuki has the has fixed issues with the years 08 and up. There is also rumor that for 2012 the M109 will get a facelift.
6. The only pain in the but maintenance issue with the bike is checking the oil. Suzuki uses a 15/3 method and if I posted it up it would take a full page. Others use a "cold check" method that others have verified and seems to be the most accurate method. I use the cold check method myself.
7. If you can work on a Spyder, working on a M109 is real easy.
8. Some seem to have clutch shudder issues, this seems to be a clutch lubrication issue, that is solved by running certain oil weights, dino & synth oils.
All of the issues have been sporatic pretty much like the some have issues with their Spyder's here. Again I wouldn't trade mine for anything. It has never standed me on the side of the road. Let me know if you have any more questions ans I will try and answer them. You can also go to m109riders.com and read more. I am under the same screen name there as well.