Lenses I've sold...
18-55 mkI - liked - got some great shots with it
ef 17-40L - meh - never impressed me (on 1.6x)
ef 28-135 IS - liked - good working distance
Quantaray 70-300 f/4-5.6 - meh - poor color, af, sharpness. Replaced by the 100-300 f/4
Sigma 100-300 f/4 EX - loved - best daytime field sports lens imo
Tamron 17-50 f/2.8 - learned to hate - it was a loud pos
Sigma 18-50mm f/2.8 EX DC Macro - meh - def better than the Tamron 17-50
Sigma 70-200 f/2.8 Macro - liked - without the IS it's not half the lens the 70-200 f/2.8 IS is
Sigma 20mm f/1.8 - liked - an "art" lens. My copy was very sharp.
MP-e65 - loved - sold for lack of use
28mm f/1.8 - loved - when it was on my 1DmkIIn, it was the perfect AoV
50mm f/1.4 - meh - I had an exceptional copy, but I just don't use this FL
30mm f/1.4 EX - disliked - AF was a train wreck (returned)
50mm f/1.4 EX - disliked - AF was a train wreck (bokeh was beautiful though)(returned)