Kenko 1.4X DGX original
I bought the teleplus Pro300 DGX when it first can out. Has worked on every lens I put on it. Canon 85 F1.8, 50 F1.8, 70-200 F2.8 and Tamron 28-75.
Replaced my 70-200 with the version II and it hunts constantly in bright outdoor light or any other conditions. Also the camera does not recognize it mounted because it still shows f2.8. Always showed 1 stop less on all other lens's.
I have debated about getting the Canon 1.4X III when I upgrade the lens. Decision is now made for me. I could just get the DGX with the Blue or red or what ever dot is the newest but I would always wonder if its as good as it gets.