Haven't seen much of them, but I don't think you'll have a problem with power... while their engine horsepower is not necessary the highest in the upper ROC categories, they have a TON of axle torque. It appears that Deere has done a fine enough job with the 300-series to make most people forget about the failures on the 200s; the Deere machines won't be selling like hotcakes immediately, but you can bet that they'll be turning heads again.
Again, to be honest, I haven't seen or heard much of them at all.