I like my 150 Nikon. Make sure that the Sironar's and Symmar's are the multicoated versions. Some early versions might not be. As people say they are pretty much the same in performance so get the one in best condition. Probably the best 150 is the Sironar S. If you can afford it go that route. Don't forget it may cost more but also has better resale value if you need to sell.