Since I've owned 3 Ninja 300s (2 white 2013s and a white 2014 with decals and ABS) I want to get an R3. I just trade a lot and although there were a couple of issues with the Ninja 300...fairing gaps on all three even though I only had the 2014 gaps fixed, dying when you pulled the clutch in on both 2013s, which was eventually fixed with new ECUs, but after I had already traded both of the 2013s in. The 2014 was a much better bike for me since they had fixed the stalling issues. Compared to the R3, the Ninja has a slightly higher seat, a slightly longer wheel base, a little larger gas tank, a slipper clutch standard and ABS optional, and a tried and true engine and fueling. Kawa is noted for their engines more than their fit and finish. I don't think you can go wrong with a Ninja 300. The R3 should be a little faster, accelerate a little faster too, but I doubt that will be significant unless you are racing. Really, I would look at other things if I had never owned either bike...cost, are there used bikes available that would serve my purpose, is one dealer closer or better than the other, which bike do I think looks better, how important is ABS and a slipper clutch (because the R3 has neither in the US), and do I want the bike very soon or will a month or 2 or 3 still be OK?