The new KQ design put into service in 2009 with power steering is excellent. With the 2013 models we are on the 5th year of the same design so all the bugs are out...but there were not many, even from the start. In both the 500 and 750 you have a very stable platform with no quirky bugs. Stop by the KQ forum...no frame issues, no PS issues, no motor issues, no oil in the air filter...rather than looking at what an ATV has for features, you might do as I did and start looking at what a particular ATV doesn't have for issues!
When it came time to buy a new quad for the wife last fall (she rides hard and loves to jump) I went with a KQ500 with PS and put elka stage 1s on it. Now she has the plush ride of an XP with reliability and lack of issues. The longer we have it, the more we like it. The engine braking it fantastic without the ADC issues. It does not "grab" hard and try to throw you over the handle bars going down a steep incline. It works on all 4 wheels, not some combination with 4 different parameters that must be met before it activates. The fuel economy is incredible...in 2 wheel drive riding nice you are in the mid to high 20's, fully 2x the range of myy 850 xp EPS...you never have to wonder if the front axle is locked in or not...you decide. The shifter is so much better than the XPs...not even a contest. Separate brakes controls for front and rear...with a sealed drum for the rear. Lighter weight, more maneuverable...and flat out the smoothest single cylinder motor you can get on an ATV. Transmission engages at lower revs and is geared higher so you almost never "race" the motor. It is quiet...you can pull over and have a conversation with helmets on without shutting it off.
I could go on, but this recent review of the 2013 750 kq is worth watching:
2012 Polaris Ranger RZR 570 test review. ATV Television. ATV. UTV. SxS. Tests Videos and Information. Latest News. Product Reviews. Ultimate Adventures
Bottom line...I have a 2010 850 XP EPS. I have been one of the lucky ones, no real issues other than horrible gas mileage no matter how I ride making me the guy always begging for gas on group rides and slowing everyone down looking for fuel. My range is 50 miles. With an average trail speed of 15 mph where we ride, the 850 ccs are rarely used, but every ride I lament fuel. I would have went with a 550, but all the valve issues and a test ride of that rattling, shaking motor ruled it out. I have replaced every bushing on it with new ones made by a member on this forum. It will be interesting to see how they last.
My extended warranty runs out in Aug and I will be selling the XP at that time. I will have over 2000 miles on it by now and don't want to press my luck with something major going out. My next atv will definately be a 750 or 500 kq with elka stage 1s, a quality air filter and bighorn tlres.
I understand those who have the $$ to chase the big bore, big size, high performance machines and say more power to them.
For me it has become more important to have something that gets the job done with a minimum of issues and peace of mind.