The pros and cons are numerous for both lenses... The suggestions to rent them and see which you like are spot on, but in all honesty you can't go wrong with the original 12-24 f/4 AT-X Pro. The AT-X Pro II changed the coatings to reduce flare (I haven't had much of an issue with flare on the original) and also added a built in AF motor so it would work on Nikon's cheap bodies, but I've heard it's noisier and slower than the screw drive on the original. The 12-28 obviously adds the extra 4 mm of reach, and is supposedly a skosh sharper... It's also $200 more than a used copy of the original. These lenses are built like tanks, and the original has fewer parts to break seeing as it doesn't have the motor. The 11-16 is a completely different animal. From what I've heard it's noticeably sharper than the 12-24/28 and of course has the extra stop of light gathering, which of course means it's significantly more expensive.