I have been messing around with my suspension settings for a long time. I trawled the internet for recommended settings, read up on it and made my own adjustments. The stock settings are for riders much smaller than I am (6'5", 235 lbs), and I knew that the stock settings were too soft for me. With increased pre-load, the front felt a bit harsh, but still much better than stock. I was not convinced that a suspension set-up by a professional could justify the cost, and I was sure that I could fix the iron out the problems with more fiddling.
My front tire wore unevenly, and my mechanic confirmed that the forks were slightly bent when my stationary bike was bumped over by a car (driven by my dear wife) some time ago. I started looking for new forks, but my mechanic recommended that we send the forks to The Suspension Shop in Adelaide, South Australia. They straightened the forks and replaced the springs, valves and fluids to suit my weight. What a difference! The ride is firm, but still comfortable. It does not dive much under braking, but still soaks up bumps in the road without unsettling the bike. Handling is secure and it corners like a dream.
I have invested quite a bit on accessories for my bike during the past 3 years of ownership, but this has definitely been the best money spent on it. Before forking out money on go-faster bits, consider having your suspension tuned by someone who knows what he is doing. You might be pleasantly surprised.