Fantastic images birdie. I found your site from an article on the use of a 1.4 TCIII with a 500mm. I too have a TCII and am considering the switch you recommended. I'm glad I check out your images because I now have motivations to increase my flower photography.
Well done. BTW, was the flower the butterflies and humming birds were feeding off actually a Zinnia?
Best wishes and good light.