the best mod by far that i have done to my bike would have to be a set of forged wheel makes the bike feel completely different and more consistent. could tell an awesome change in power to i have done just about all the bolt on items that you can to my r6 and the power gains were good but just me putting the wheels on my gsxr it made all the difference wondered why i did not go that route before. working on the suspension is is a plus on these bikes i think that it is the best money you can spend. i have a hyper pro damper i also put in nology iridiums bmc air filter new sproket and chain same amount of teeth but about 3/4 lbs lighter and about twice as strong. i upgraded to galfer brake and throttle lines the throttle worked really well the break was about the same just more comfortable knowing i have the braided lines now. also have a power commander usb III and an ignition commander which in my opinion made the power commander actually useful. i have not changed the exhaust yet kinda seeing what is coming out for the k6's still, right now i am stuck on the micron but they are coming out with an exhaust about every month now. so i can wait some. can't wait to take off some more weight with the exhaust now my wet weight is now 398 from supposedly 411 which i did not check before my mods but it definately feels lighter. the exhaust i am expecting to loose 15 lbs or more so that is a plus on the diet side of things lol. my peak horsepower is only up 2 hp at the motor but i am putting almost 4 more down at the wheels and my torque is up .6 lbs at the motor and 1.1lbs at the wheels definately feels like a new bike after the full exhaust system is on i want to take the 112 at the wheels and try to make it to 121 we will have to see how that goes and i want to try to add another 1 lbs of torque at the wheels. that is my project on my k6 now that i look at i am almost finished only about 1500 more dollars i have put in about 3000 already so i will be content all in all out the door and everything i will have 13000 grand on a new bike that is awesome just hope i don't try to do the same to my 749s i plan on getting next summer. lol if you have any ideas i am open or just let me know what you did on your bike.