The rear sprocket is a matter of taste, I like it and look much better all black. But your chain should have been spot on! Mine fit perfectly. No cutting link required. The chain should not stretch that much... I always set mine towards the minimum slack when new and never touch it afterward. One of the good thing about having only 70 WHP... not too hard on equipment! LOLSo. I put them on. More details are in another thread.
http://www.600cc.org/forum/f87/what-did-you-do-your-bike-today-20806/index237.html
The rear sprocket was heavier than stock. I don't like that. The front was missing that cool rubber-molded piece on each side. I'm not sure what it does, but I'm guessing it lowered the noise of the chain going over the front sprocket. I hope I don't miss it.
The rear sprocket was obviously designed to fit many different bikes. Different size holes all around. Some of the holes had an inset for a washer. Pretty cool, but those holes didn't fit the bolts on my rear wheel. The larger holes did. The insets on the holes I didn't use look pretty fugly. I don't like that, either. The backside of the rear sprocket just looked unfinished, so I had to put the side with the washer holes out.
The front sprocket has a rib around it on one side, that the stock didn't. I had to guess which way it went in. I think I got it right.
The chain is too long. I'm at the next to last nick on the indicators on the swingarm. I should have taken a link or two out. Tyler told me that the link count was set at the factory, and it would be correct for the bike and sprockets. That's OK. When the chain stretches, I'll just cut a link out and keep riding.
Overall, it's not an OEM. I'll suck it up and drive on. The price was good, and the name bespeaks good quality. My issues are honestly pretty minor, if I get a whole lot of miles out of it.
As always, time will tell as to quality.