I used the 500/4.5 in the past and it is a fine lens. However, the lack of IS, greater MFD, and especially the loss of AF with a 1.4 x killed it for my needs.
That is all true, except I've never tried to use it with 1.4xTC......in theory it should have AFd with 1D bodies.
However, the key strengths for me were its relative ease of hand-held shooting and IQ very similar to 500 f/4 IS.
In fact, if it was not for the introduction of 500 II, I wouldn't have sold my 500 f/4.5L. I would have kept it as a lightweight alternative to my 500 f/4.
24 TSE - I donít know what it does, but if I had one, Iíd find out
50 2.5 Macro
70-200 2.8 IS
85 1.2 (FD mount lens, itís beautiful)
100 2.8 Macro
200 f2 IS
300 2.8 IS
400 2.8 IS
So that's 16, the best I could do. I guess the last four would be old FD lenses to mess with