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.