If you want to drag anything on a sidehill forget the IRS. They are scary on a sidehill anyhow. I run the local ATV club and have to do it for them all the time. As for what size a 500 or above will do just about anything But thats not the point . What do you want to do I.E. if you were some non hunting, tree huggen uninformed fool that lives in the city I would say go with a 300. If I were a real man I would go with somthing 700 or bigger that dont way 800 LBS (Polatsky) I am not a big IRS fan eather. If you want ride to be your first consideration go IRS if you want to have some fun and work the unit go SRA. There are some exceptions (rock cralling for one) . I will explain why if needed ( I sold my 660 IRS to go back to a SRA ) and for me and my style of riding SRA is the only option (after 20 years of racing Im not ready to sell out handling, solid feel, power sliding, for a soft ride and ground clearance at one point on the quad ) But many are and most of them love them. So its more about who you are Im thinking 700 SRA [img]i/expressions/face-icon-small-smile.gif[/img]