I had the opportunity to ride one once (a 300E) for a few miles. It was VERY powerful, more than I would ever need in the woods. It is a beautiful bike - very trick looking.
The one I rode was probably not broken in yet, but the suspension seemed stiff and valved for more agressive and high speed riding. FWIW I talked to a 250 pound agressive A rider that races one and he thought it was too soft stock. IMO Paoli forks can be made to work wonders with the right valving (Factory Connection did the right side up Paolis on my bike and they are MAGIC).
Certainly comparable to a KTM300 in power - maybe even faster although it was icy when I rode the bike and there was no way to get it up in the rpm range. It's ridiculously fast. Big, strong, in-shape fast guys would love it. Wimpy spodes will get tired hanging on, IMO. Plenty of meat down low for lugging, serious open class power when the revs pick up.
Front brake was strong but had a much different feel than my Honda (more grabby, IMO). The bike has a very Euro feel - similar to KTM, whereas the Gas Gas feels more like a Japanese MX'er. To me the TM did not feel very flickable, but it was stable.
Overall, the bike did not suit my riding style (I could go much faster on my 250), but in the right hands and with a little dialing in the bike would surely be competitive.
My personal opinions on the TM enduro are:
Reliability - the most relieable dirt bike made.
Power - my 125 is very pipey, but has lots of flywheel so it hooks up. I've had friends that are 200+ lbs that were impressed that they could make the 125 go. The 250 and 300 have very linear powerbands (no low end or mid range hit), and are deceivingly fast.
Suspension: I have the 46mm RSU "Blue Steel" forks and they are as good as it gets. The 46mm USD forks may need revalving for your use (I see you live not far south of me in Seattle). The Ohlins rear end is excellent.
Handling: Stable and easy to ride hard and in the rough, but doesn't cut like a CR or RM. Very non-tiring.
Detailing: Made to last.
Complaints: Clutch drags, oil filler hole is too small, some vibration.
Bottom line: The TM works well if you like smooth power (lots of it), slow revving (tractible), and if you pick smooth lines rather than "super crossing" the trail). If you root in the mud like a pig for 9 monthes of the year (like WA state), seriouly look at the TM).
There is a dealer in Renton that has a full line of TMs in stock (they also sponsor Brian Bennett in the NMA rides and the AMA reliability enduros).
I prefer a stable handling bike, so I like the TM. Nobody that has ridden my bike has complained about slow handing. The weight of the bike is inline with the competition (note: a few years ago DB mag. showed the TM250E to be the lightest 250 enduro bike in their shoot out). As noted by dirt bike dave, the brakes are awesome!!!!! (270mm front rotor). Stoppies are no problem. I wouldn't say grabby, just strong. The TM is a professional quality machine that is available to the public in limited numbers.
I ahve a 1999 TM 300E the bike is awesome, quality of bike is incredible.
The power is really good, the handling is great. I lowered the triple clamps on the forks 5mm for tight woods. No problems at all with the bike. I rode a
friends RMX last week seemed to have to rev it all the time to keep it up in the power, seemed looser in the handling. The bike feels not as nervous
as the RMX and lighter. I took the lighting coil off didn't like the way it
revved, put the fly wheel back on loved the way it was smoother, less clutch.
Best bike I've ever owned. Can't go wrong for any conditions you ride in.