I have Canons top zoom, new 500 and the 300. Im no pixel peeper and if it needs to be said Ill say it. If its good, ill say its good, if its bad ill say its bad. I rate Canons top primes at 9.9/10. The new ones are damm near perfect. I have Canons top zooms which I rate at 9.9/10 (for a zoom and damm close to a prime). I rate the new 300 10/10. Lazer fast autofocus, less weight, 4 stop IS that works, etc etc all good. But for some reason and I dont know why, every time I take the 300 out, the pics I get back have an x factor I have never seen in another lens. I love Canons new lens's but the 300 is king.