Let's see...
The question isn't TROUBLE-FREE service time, but just time in service. I assume this means as long as in-home repairs are possible and performed, then that's "in service time."
So, my main HOTAS is a Thrustmaster FLCS, a Thrustmaster WCS Mk II Throttle, and a set of CH Pedals (non-pro).
All were purchased in May 1995, or so says my notes in the M50 programming files.
Average gaming time (include some space sims too) is 10 hours a week for 40 weeks a year (some weeks I don't play - magazine deadlines) is 400 hours a year. Times 12.5 years = 5000 hours. And that's probably very conservative.
Over that time I've had to replace the foam pad under the two-stage trigger twice (it degrades and compresses - a thick mousepad shaved down to fit is a good repair). I've replaced the S1 button on the stick once, had broken a hat shaft and replaced the whole hat (H3 if you must know), and replaced one plastic trim ring that holds down the rubber boot once. I've superglued the throttle handle to its shaft after it broke in transit to the 1999 WB Con, and then epoxied it at home when it broke again on the trip back, and what I thought would be a temporary repair at best has lasted to today.
Just this month, the CH rudder pedals started spiking, so I cleaned the pots with Tuner Cleaner and it has helped. New pots are arriving today and I'll replace them over the weekend. The throttle's pot could probably use a cleaning too, but the joystick's are fine.
And just in case, I have two spare FLCS's and two spare WCS's for parts or to be spares if these ever totally fail, two F22's and TQS's in case I ever decide to switch or get a set of Bob Church's digital StickWorks chips (if you have a set to sell, please contact me!!!). I also managed to get a very complete parts kit from TM the week before Guillemont bought them out. Obviously, I really love this stuff.
I already have patched gameport drivers that are Vista compatible if I ever have to switch over from XP, but I don't see me doing that for many, many years. I've tested all the hardware with a Vista box, and it all works fine.
And don't forget, this was *your* question. ;-)
-Llama