Just received the Canon 1.4x TC3 and been trying it with the 70-200 IS2 and have to agree, the combo is very good thru out the zoom range. Pretty amazing just how little the IQ degrades...as in probably not detectable in most blind A/B's of pictures of actual subject matter.
It's the same thing with the 200L f/2.8. Having this kind of IQ @280 f/4 in such a compact, light weight, black package warrants keeping the 200L even though I have the 70-200. Especially if I add a crop body and something this small shoots at 448 equivalent.
Glad I sprung for the Canon piece, nice build, guaranteed compatibility, registers the combo for AFMA. Had some B&H bucks from buying the 70-200 so between that and the current rebate, scored this for $335.
Thanks again for fielding my questions and what to expect from it.