Probably the best money I've ever spent on the bike was putting aftermarket suspension. While we've used Cogent Dynamic Motorsports, Works Performance and Ohlins, my "go-to" guys is FastBike Industries. Pronounced "Oh-leens", David at FastBike has been able to some great work. He's a independent shop, but a perfectionist. Furthermore, he understands that models and the science behind the numbers. He's such a wiz-kid, that he is able to do entirely custom work.
For example, instead of cutting down an incorrect spring rate on the cartridge inserts, he actually gets custom wound springs. Surprisingly, getting the correct springs doesn't drive the cost much. So, I sent him my front forks. He reused the fork tubes, but modified the cartridge inserts (used on the F800GS) for the XC and my parameter (shorty!). The front forks now have fully adjustable rebound and compression settings.
For example, instead of cutting down an incorrect spring rate on the cartridge inserts, he actually gets custom wound springs. Surprisingly, getting the correct springs doesn't drive the cost much. So, I sent him my front forks. He reused the fork tubes, but modified the cartridge inserts (used on the F800GS) for the XC and my parameter (shorty!). The front forks now have fully adjustable rebound and compression settings.
For the rear spring, he actually specified each sub-assembly to design the custom shock. Ohlins are naturally 'taller' than stock, mostly due to the fact you normally correct the sag measurement. To compensate, he was able to shim it a wee bit (think mm).
Since there are few bikes that really fit a shortypants like me (28" inseam), I fully expect to have to spend $ modifying the bike. I also keep my bikes long enough to enjoy the aftermarket investment. The suspension work (AKA 'Spench) was probably 50% of the value of the bike, but something that work is the best Return on Investment that you will notice!
A few months later I took the XC over to a cornering clinic. Basically, it's a closed 10 acre course that is coned off. While knobbie tires, I was putting the sport bike guys to shame because the 'spench was settling so nicely. Needlessness to say, those TKC weren't coming home with "chicken strips" today!