I had a 12 polaris and now have a 12 Brute. My riding group consists of polaris, canams, hondas, and Grizzlys. I have ridden all of them on rough trails and we ride hard and fast...There are compromises to ALL of them...there is no way around it. FWIW, here are my thoughts:
Brute Force - just as the name says...it is a Brute...cruder and rougher around the edges than others. Hardest hit off the line (except for a 1k renegade). They are a rocket off the line. Stock suspension sucks...I have elkas and it helped tremendously. Needs more maintenance than others
Hondas - dont matter which one..rincon, rancher, etc...bulletproof reliable, less power, less suspension, and more made for farm work imo
Canam - outy 650 and 800xt's - higher priced, best motor (imo) there is. Clutching is very soft though..they are soft on the bottom end....suspension is way too soft for the speed they can hit on the trail. Priced higher and several seem to have electrical gremlins. These pigs are heavy. The 1k is a beast...I love the renegade 1000xxc, but I need something with racks for hunting and such...and you get plastered with mud on one
Polaris - best stock ride of the bunch. Lots of power, but it is very smooth...nothing like the Brute...the Brute hits a lot harder off the line, but the Polaris has a lot more power (smooth) and blows past it pretty good. Have been repeated issues of busted a arms, axles, etc. When something that big and and heavy is ridden hard, something usually breaks...same with canam (they had some frame issues last year)
Grizzly - less power than all the above except honda, but is likely the most well rounded, all around big bore out there. It doesnt do anything bad..it is light and nimble and ultra reliable. The riding position is a bit too cramped for me, I dont like the seat and the 2013's and earlier were tippy..the 2014's are about 2 inches wider and are much more stable. The Grizz does everything good...but it doesnt excite me at all...but they are tough, dependable quads that can go over and through about anything.
I like them all...but I also dont like a lot of things about each one...I have 1300 miles on my Brute and love the sportiness and the excitement you can have on it...elkas make it ride like it SHOULD have ridden from the factory (I cant stress enough how bad the stock shocks were). But even with Elkas, it gives up some handling to the Polaris and others...you can only do so much with the limited suspension travel. Also, I am afraid it will start nickel and diming me to death.
If the Grizzly would have come out in a v twin platform, I would be all over it (add elkas and rox riser and flexx bars and be golden), but that aint happening right now. Outy needs aftermarket shocks, unless you go with an XTP...but those are running 14k....way too much imo.
I will likely go with the exact one you are looking at (the xp850 LE). Nice package, good price for what you get. A clutch kit to get some bottom end response and some braces from a member here that is making them to help with the rear a arm issues and I think a person would be good to go for aggressive trail riding, casual trail riding, hunting and hauling stuff...all without the cost of the outy 1k xtp. If you ride hard enough, ALL of them will break something imo (although the grizzly in our group has never, ever had an issue in 1500 hard miles). Go ride them all and see what feels best to you...only way to know for sure which is the right choice for you. Good luck!