All Brutes are liquid cooled aka Radiator being big V-Twins.
As far as I know the 12's really come in 2 flavors- EPS or not.
The red ones are Non-EPS.You pay a little more for Camo or Special Edition which gets you a rim upgrade and pretty painted plastics.Green and Black models are identical with EPS.I highly recommend the EPS.This big Quad requires almost zero effort to point it wherever you want it to go.Steering with one hand in tough spots is not an issue.Purists say it is one more thing to break and like the old school feel.I'm 45 years old so I'll take all the help I can get!
I have a 12 that I put about 220 miles on so far stock except for a winch and a bag and so far I love it.Zero issues.
This is my first ATV so I have nothing to compare with but so far the stock tires aren't all that bad.They have gotten me through some rough stuff no problems and my first ride was in a downpour and I had no traction issues.
That said I will eventually upgrade the tires.
Lots of great deals on leftover 12's-shop around.
Rocky Mountain ATV has good prices/service on accessories,not sure about OEM stuff.
Here is a link to places to buy stuff: