What are you looking to get? I have eight lenses from 45mm to 200mm and they are a mix of new and old. My opinion, for what it's worth, is that they are just like women in that they are all good, but just somes a little better than others. My 75mm, 135mm and 200mm are the older version and I find no reason to do any upgrading for any of those. Likewise for my 55mm! I have the second version and find it all the lens I could ask for. My 45mm is the newest along with my 165mm LS lens, but I find my 45mm lacks a little in the contrast/sharpness range until I get to between f8 and f11. It's still one mighty fine lens regardless. Like I said in the beginning, "They are all darn good"!