I do not have that many hours on mine yet.
It has plenty of pulling power. The engine seems to have a lot of low end torque. The engine goes to 3000 rpm quite quickly off idle but even climbing grades with a lot of logs it will still be under 4000 rpm. I had it floored a couple weeks ago to see how fast it could go. The power curve drops off over 5000 and had it near 6000 at about 39mph before I had to slow down. It was still climbing but after 35 or so the speed increase was much slower.
My primary preventative item is using ethanol free gas with a stabilizer and keeping the tank full. I also try to keep the battery at full charge by hooking it up to a battery tender.