The DRZ is far from the last word in race performance as they are too soft, too heavy and don't have mondo power. Don't take this to mean they are turds though. They are excellent "serious trailbikes" with smooth strong midrange power and lots of revvability. They are not explosively powerful though, at least not unless you throw your checkbook at the motor with big bore kits and cams, etc.
The DRZ has an innate ability to cover gnarly ground at a good rider's 80% pace for hours without unduly tiring the rider. Push for that last bit of speed to get up to race pace and they will tire you out right quick. Ya gotta be honest with yourself about what you want it for. I consider the front forks on my DRZ, with one step stiffer springs and Silkolene oil in them, to be the finest off road forks I have ever ridden behind. They remind me of my '87 CR250. Plush city in rocks and such.
The DRZ is reliable. I change oil every 300 off road miles using Rotella T, do the filter and ride it some more. And adding a Yosh exhaust really wakes up the throttle response. The engine holds 2 quarts of oil and it is a solidly constructed unit. This makes it a bit heavy, but it also makes it reliable and low maintenance
I would not pay much over 3K for a used one though, even if it is in perfect shape and nicely modded. Too many off road bikes available that are later and greater. They are selling new '06 WR450s on Thumpertalk for $6,100 plus $245 shipping :hail Seems the '07 model has an aluminum frame and they are blowing out the '06. That pushes the prices for used dirt bikes down.
Anyway, here are a couple of pics to entice you :laugh