I do agree.
a german photomag does lens tests in combination with DSLRs for have a year now. Normally I don't trust those magazines. But they seem to have done extensive research and provide the results for a certain lens in conjunction with exactly just one camera. Even Nikon D70 and D100 are seperate.
Naturally I did not read the Nikon D70 or D100 charts ![]()
But the Sigma 50mm and 105mm Macros were better over the Canon originals. The old lineup (non DG Series) were better as well.
The Sigma 50mm was brilliant already wide open. The Canon started to come alive stopped down one unit.
I consider to add a 100mm to my Sigma 50mm. Only advantage is Canon's ring type USM with fulltime manual focus (only the 100mm, not the 50mm) if one wants to use it.
I think you can buy the Sigma Macros without any doubt.
Julian