sony 16-50mm f2.8 are not g like lens

Im tired of listening that 16-50 is g lens. they are not. i own them and i would pay 400$ to change   for 16-35 CZ  

sony 16-50mm f2.8 ssm VS  sigma 17-70 f2.8-4.0 hsm

here is the truth:

http://pliki.optyczne.pl/son16-50/test/son16-50_fot01.JPG

sigma:

http://pliki.optyczne.pl/sig17-70OS/sig17-70_fot01.JPG

and the zoom ring is stiff. is that correct word?