If you have no need for Utility (i.e. hauling gear, pulling, etc..) and you don't mind being covered in mud then get the Scrammy. If you want utility then get the sportsman! You can't go wrong with either but if your all about going fast, jumping and so forth then you want to get the Scrammy as it is geared towards that application.
I have the 850 XP and I am never short on power or speed but I don't race and I don't jump (much!).
The first thing I bought for my XP was Fender Flares as I would just get doused in the mud (especially if spinning the tires). The mud flies straight up and drops back down on you. On the Scrammy it's an ever worse bath. The Fender Flares on the XP worked perfect and they usually keep my pretty dry and free of mud.
Not sure what is available for the Scrammy? I'm 47 and ride hard but I don't want to be covered in mud or wet all day after 10 minutes of riding as we usually spend 10 hours a day riding. I can ride my XP through Mud coming over the front end and still be halfway clean after the ride.
2010 Sportsman 850 XP (Dark Green)
Polaris Front and Rear Bumpers
BlackWater Evolutions on 14's
Polaris Front and Rear Lock and Ride Cargo
Custom Bags on Cargo
Ricochet Ultimate Skid Plates
(Orange Anodized A-Arms)
Polaris Hand Guards
2- 1 Gallon Rotopax's in front storage
New addition: 2005 Honda VTX 1300R