I myself use engine guards & highway pegs on my 9. Seems that if you legs are that much foward it can be a lil tricky when you go over bad roads with alot of ruts n bumps. Where as if your pegs are somewhat under the center of the bike, you can stand up a bit to lessen the impact when you bottom out. Sorry just my 2 cents buttin in there. I also have long legs & its a lil bitter to have 2 docking stations for your feet. IMHO
I'm not sure if you have tried sitting on a bike that has them yet or not, but I would definately recommend it. I desperately wanted a set of forward controls too for mine, but then I got a chance to sit on a bike that had them and found out that they are way too far forward for me. I found that my legs were pretty much straight out to reach the controls. I am 6' tall too, so my legs are by no means short. Just my 2 cents as well...
I'm 6'8" and went ahead and bought the Raw Design forward controls. They are simply awesome. They moved the corntrols forward about 3 inches and now I have room to relax. They are expensive but well worth the price. You have to remove your engine guards but I get compliments all the time.
I think that they are useless, unless you are quite tall or long legged (taller than 6'2 or have a inseam 34 inches or grater).
I am 6'5 and sit with my knees at a 90 degree angle when on the M109. I haven't yet been able to justify the expense of them and i'm kinda waiting for the Supreme Legends version. I certainly would have loved to have them when I rode to the Mid-Atlantic in June.