Last season, I sold my '06 Attak & bought a new leftover '09 600 Etec Renegade.
The Doo had a small coolant leak that was repaired via warranty. This did not cause any loss of riding, was minor & was not a big deal as many will make it out to be.
The cornering on the gade was absolutely phenominal. Zero ski lift & it will hold any line in the turns you wish. I've driven them all, the gade is the best cornering sled I've ridden.
The rear suspension is excellent. Not as absorbant as a Nytro XTX but the Doo rear is very good. I had the Adreneline model w/HP gas shocks. I did experience shock fade when riding very quickly up in the County. The corner ability on the gade is dangerous. It is not necessary to slow down & I very often found myself going way too fast simply because the sled corners that well.
The ergos on the gade were very good. Rider position was very similar to my Attak & better than the Nytro XTX I rode. The Nytro handlebar position, regardless of how it's adjusted, I never found to be comfortable. The Doo can be ridden all day comfortably. It is far, far less fatiguing than my Attak was & far, far less fatiguing than a Nytro XTX. At the end of the day, no aches or pains or fatigue & I'm 50 yrs old!
The Etec motor is as advertised. Quiet, smooth (but obviously not as smooth as a 4 stroke) & had a consistent pull thru its rpm range. It went from 0 - 70 very quickly, probaly as quickly as my Attak but it got winded after 70. It would touch 100 but it was a struggle to do so. Midrange was ok but not arm stretching by any means. Being a 2-stroke, it was 'buzzy' which is to be expected as compared to the turbine-smooth Yam engines.
The Doo is not as well crafted as the Yam but that's a 'known'. Yam quality is leaps & bounds better than any other brand. The Doo's fitment & 'feel' is not as awe inspiring as Yam. That said, I had excellent luck with my gade but I only managed 1,100 miles last season.
I enjoyed the handling & the ride immensley on the Doo. The lighter weight & lower Cg is a major, major advantage over the Yam. I do miss the torque of a 4 stroke but I do not miss the tippiness, weight & rider fatigue of a Yam. The Doo was much more fun to ride on the trails but the Etec did not have the stones for frequent, hi speed running like what's done up in The County or in Canada.
I have sice sold my Doo only to keep my finances liquid, I was in no way dissatisified with the sled. Depending on finances this winter, I plan to ride an '11 Apex to see if it truly is an improvement over my '06 Attak. If so, I may go back to Blue but it is a coin toss.
If you have the money, keep your Nytro, buy an Etec & decide from there. If you do decide to buy the Doo, you will not be disappointed.
I've ridden lots of Nytros & never felt comfortable on that chassis. Perhaps you may also want to conside the '11 Apex, it gets lots of good preliminary reviews.
Happy trails & here's to hoping we get more snow this year than last!