I have both a ~1999 Mk 1 and 2018 Mk 2 100-400. The Mk 2 is waaay better in almost every way: focus accuracy, no push-pull, better bokeh (marginally) better con

I have both a ~1999 Mk 1 and 2018 Mk 2 100-400. The Mk 2 is waaay better in almost every way: focus accuracy, no push-pull, better bokeh (marginally) better contrast… just better results with less effort. Also a lot more expensive. I have three different TCs which I got from a friend who switched to Sony. I haven't really used them much because they seem to drastically change the optic behavior in ways I don't like. Maybe I should give them another chance as they never come out of their cases.