I thought I was doing okay using my 300 2.8 AF-I with 2x TC as a long lens but I had no idea how many shots I was missing due to focus hunting with the TC until I got my 500 AF-I. I use it primarily without a TC.
As a recent purchaser of this remarkable (and expensive) lens I had the occasion to use it extensively on a four day workshop led by Jason Odell at the Campos Viejos Ranch in south Texas. Below is a capture of the very colorful Painted Bunting...
The skimmers have arrived for the season. A handful of these elegant tern-like birds were entertaining me at Prime Hook NWR this evening. D800, f/5.6, 1/5000, 500 mm, ISO 1600