Depends, with the modern high ISO performance the light is not really an issue anymore. AF can be a problem because that is done with wide open aperture and the lens is of course not a f2.8 lens.
But yes I would advise it, I think for the money it's a great lens.
After almost a year, are you still using this lens? Are you still satisfied with it? I'm curious because I'm planning to purchase a lens in this category and the Sigma is one of the candidates.
Surely it's good to read all the reviews when a lens is new, but I think it's even better to know someone's opinion after using it for some time.
Even on the 5DKMII it keeps it's quality. I'm not shooting that much at the moment with the lens because my schedule is very busy so I don't have much time for anything else than the workshops and fashion shoots. But I did some work with the 5DMKII with it and it's still a wonderful lens.