Canon 100mm USM macro vs Sigma 105 EX DG OS HSM macro

My friend is looking for macro lens. Options are Canon 100mm f2.8 USM and Sigma 105mm f2.8 EX DG OS HSM, both used. Only difference is, Sigma costs 60USD more, but comes with warranty. My friend now uses Canon 2000D but in the future will go to full frame body . Lens will be used for food photography, babies and products.
I have 100mm macro L, so these lenses are unknown for me. What is your opinion? Is Sigma worth extra money?

I have the EF 100mm f/2.8 USM Macro. It's the version without IS, but it is internally focusing and has a USM motor, unlike the earliest EF 100mm f/2.8 Macro, if I remember correctly. I have never used the Sigma 105mm. My 100mm Macro is very sharp, has pleasant bokeh and makes a good portrait lens as well as a macro lens. The only complaint I have with it is that it is often very slow to focus. Being a macro lens, it has a very long focus travel, and sometimes it will miss focus and rack back and forth unless I manually focus it. Other than that, it's pretty nice.

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I own the Sigma, and have been happy with the lens. I do not shoot much macro, so couldn't justify the cost of the Canon 100mm L lenses.

I don’t have the Sigma 105 macro, but I do have the Sigma 70 and 50 mm macro lenses. I also have the Canon 100 macro non-L. The Sigma 70 is probably as sharp as the Canon 100. AF is faster on the Canon than either of the Sigma lenses. I don’t think that the Sigma 50 is quite as sharp as the others, but this is subjective.
All macro lenses are sharp when stopped down.
The only advantage of the Sigma 105 is the OS, if it works well. The Canon 100 macro is a great lens. It is a tough call. There is always a small gamble regarding AF accuracy with large aperture Sigma lenses, but AF has been fine on my Sigma macro lenses. My only gripe is with AF speed with the Sigmas.
The Canon has a focus limiter, and this helps improve AF speed when shooting at normal distances.

Thank you all. Looks like both lenses worth the money so we decided to contact sellers and travel to check both lenses to see which one comes closer in performance to my 100mm macro L