I just got the 16-55, I had the 18-135 and the 18-55 before. First there was is no way to compare these, the 16-55 is prime quality. This is the first zoom that convinced me to keep the primes at home, focus speed feels like an slr. weight is not an issue,considering the magic that comes out of this lens and how fast it is to catch kids, my motto is go big or use the iPhone...took it to the beach yesterday and got splashed with sand and mud, bring it on!