For aggressive woods/x-country stuff the TC250 is awesome. I find it a bit harder to ride on tight, technical terrain and single track (compared to a trail version bike).
I actually think the suspension is perfect to almost too soft in the woods, and too soft on the motocross track. I am 176# without gear.
I like the Uptite skidplate I got. It covers the part of the frame that sticks out on the side. It could use a slot to make getting a wrench on the drain plug possible, so it is not necessary to remove the skidplate when changing the oil.
The stock gearing is too high to slow technical riding. When riding the TC250 I do not attempt steep super slow hill climbs (i would search these out on the WR125. I am thinking about trying one tooth in the rear. But have not yet, because the gearing feels perfect on the track. I find I have to ride the clutch a lot, when starting on an uphill, or in a rut, etc. on the trail (and have stalled many times doing so).
The gas mileage is pretty good. Much better than the WR125. I have not rode them back to back, but it feels like the WR125 eats almost twice as much gas. I have overflowed gas out of my TC about 4 times thinking it should be empty like the WR, and not paying attention.
Bars feel a bit low for long periods of standing. I had a couple riser spacers from my old '06 WR250 that are taller than the spacers on the newer bikes. This, along with switching the risers makes riding while standing perfect.
The JD jet kit worked very well on my bike. It has a slight stumble when I really lug it low, then try to whack the throttle...but all 4 strokes do this (at least with carbs). Otherwise, my bike starts 1-3 kicks cold, and 1 kick warm/hot in all temps. The only time I use the hotstart is if the bike has been on it side (because I am helping a family member pick up their bike

). When I kick start the bike, I do make an effort to bring the motor to just past TDC against compression and then simply give a nice smooth kick down. I do not have the carb upgrade on my bike.
Stock exhaust does seem to restrict power up top. The bike pulls the best in the mid-range, then seems a bit choked-up on top. I have not rode with the sparkarrestor out of the pipe. The sparkarrestor does rattle and give the exhaust a raspy/clanky sound, which is annoying.
I think the TC250 is one of the best bikes I have ever ridden...as a do all bike. It really does well everywhere. One thing I hate about trail oriented bikes is often the gearing never seems right when you ride aggressively on a track (I know that is not what they are made for

). The Husky trail bikes seem to be better. I really liked the gearing of my old WR250 on the track and trail. The WR125 is good, but not perfect on the track (perfect in the woods). I would not opt for the TXC or TE over the TC. The TC is greensticker! It is light. And it has very good stock suspension.
The only issues I have had with my TC is a leaky kickstart seal, and a leaky shock. Both fixed with the 30 day warrenty.
I just wonder, when I read these magazine article comparisons: why they never mention the value of the TC, the fact it is greensticker for year round riding in CA, has a sparky, and a 30 day warrenty. What Japanese MX bikes can even compare to that?
JS