I just thought that I would post an update: I ordered the 300 f/4 tonight along with the TC-14E. It should arrive here on Thursday. I thought about ordering the replacement collar, as well, but thought that I would give the Nikon version a try first.
Looking forward to the Big Brown Truck ... Larry
"Every moment in life is unique and will never be repeated. These are the moments that present the greatest opportunity for a photographer..."