I put the SuperATV EZSteer kit in my 2010 550 two years ago. Wanted it for the tracks I use in the winter. Been almost flawless - they stand behind their stuff and they replaced the part that was problematic - since changed in the kit.
I would say 3 hours would be good for an experienced "wrench turner". Not hard to do, just a lot to do and keep track of all the parts that need to be set off in order to do the install.
Recommend you read the instructions and look at the parts in the kit until you have a really good understanding of what everything is and where it goes.
It's up $100 from when I bought mine. I'd call them and talk to them, price might be reduced.
2015 Sportsman 850 in Sage Green
3500 lb. Polaris HD Winch
QSC Clutch Kit (from Ryan @ RVS Performance)
Odyssey PC925L-P Power Sports Battery
VIPair Windshield w/mirrors
HD ATV Gear Billet Pinion Cover
EPI HD Springs, Front & Rear
Cecco Frame Braces
27X9 and 27X11-14 STI Rocktane XD Rubber
Guru Bumpers, Front & Rear
Lock 'n Ride Front & Rear Boxes
Rhino Monster, Rear Box
Camoplast Tatou 4s Track System
Heated Grips and Throttle Control
Lowrance BAJA 540 GPS
SuperATV EZSteer 380
Various Mods for Ice-Fishing