08 600rr or 2010 iqr. ... Please help!!!

Ok guys I found a 08 600 rr with a 136 track usa extension and 2" paddle track. It was setup like this new from dealer and the dealer also dropped in the 600 r race motor new(it was bought in late 09 early 2010 and a 09/10 600r was put in it). It is oil injected, but no reverse because I guess you cant do reverse with the 600 r engine?? Anyway the sled is pretty much mint with under 500 miles on it. Should I be concerned about the reliability of the race motor?? What are your thoughts on it?? . I just want to see how tough the 600 r motors are. I can also pickup a 2010 iqr, . I have two 2010 iqr's in mind both low hour and mint. I think the iqr's would cost me an extra $500- $1000 , but then I wouldnt have oil injection, and I'd have to trail convert. How much different or better is the spindle/ a arm design on the 2010 iq r compared to the RR(again this will just be a trail/backcountry sled so Im not sure if it even matters for me)?? To me this is the biggest difference between the two sleds as well as the rr having the 136 on it. Let me know your thoughts guys as I need to make a decision this week. Im really leaning towards the 08 RR. Does 5K sound like a good deal on the 08 RR??

Yeah I think I am going to go with the RR. Here are some pics of it. WHat should the compression be on the 600r motor?? WHat else should I look for on it when I go to pick it up?? Yeah he was asking $6500 for it and Igot him down to $5000. He bought it new in 2010 I guess and it only has about 350 miles on it. SHould be in close to new shape.