Nikkor 70-300 with Kenko Pro 1.4

[Jim1957]

Has anyone tried the Nikkor 70-300ED, with the Kenko Pro 300 DG 1.4. I can't afford the 80-400 VR yet and would like to extend my range. I realize the autofocus will be slow if it works at all, but wonder if anyone has tried the combination. Once I can afford the 80-400, I understand the Kenko will work with it, slowly of course.