I looked at both lenses and liked the smaller size of the CZ but the 16-50 has an "Ultrasonic Motor" which is almost silent, and I can grab and turn the focus ring at any time without fear of damage (and it doesn't spin while autofocusing). Weight-wise, they seemed very close. Both looked very good on my 24" screen, though the MTF data on the CZ looks a bit odd to my eyes, suggesting abrupt dropoff in sharpness out to the corners in some situations (only took a few shots in the store) whereas MTF for the 16-50 suggested a smoother transition. In the end I went with the 16-50 and I love this lens! Only possible regret is perhaps not getting it as part of a bundle with the A77 which would have saved me some money and been a fine excuse for getting an A77. The lens kind of dwarfs my A35 but wow what a performance upgrade.