600D + 100-400mm L lens

Hi Lee

That tamron lens is really good. Mine gave better results on the 600D until I micro adjusted the 7D.

I looked at all the options before this Canon 100 -400mm came up at a bargain price.

The Sigma 150 - 500 was tested by Amateur photographer and and found to be a bit wanting at 500mm.
I think this is the case with most of the 3rd party long lenses
Best wishes
Peter