Yes, but also very amateur-like

I would also like to see some tests made with a stricter scientific approach.
Anyway, the idea I have made myself til now is: the Tamron is a tad better than the Canon MK1 (especially wide open), plus it has VC and it's cheaper. A clear winner here.
The Sigma is nice as well, very similar to the Canon in optical performance, although the Canon responds better to stopping down. The Sigma is the cheapest, but it's plagued by an awful bokeh. Tamron's bokeh is ok, but Canon's is still the best.
All in all, this Tamron lens seems a very smart purchase.