Hi there. I've recently had the opportunity to purchase a very reasonably priced second hand Nikkor 300mm f4.0 AFS lens which is yet to arrive. I intend to try it out in the field for both still and moving subjects. If anyone in the forum has experience with this lens, I would appreciate your comments on the following: 1) General impressions of the lens and the much criticized tripod collar. 2) The replacement collars offered by Really Right Stuff or Kirk Enterprises. I've looked at the designs on their respective web sites and the two collars are quite different. 3) The lens reportedly works very well with the TC14E converters. Has anyone tried this lens with the newish TC17EII teleconverter? Thanks a lot and keep shooting, whatever your equipment or subject matter happen to be. Cheers. Greg.