It does go down to f4.5, and it has a macro function for the 95mm range, but compared to fx. the Sigma 100-200mm Macro it is rather limited, since the Sigma has macro all the way trough the range, not just at the low end..
i got it for cheap, so I don't really mind it, but I wouldn't pay a lot of money for one..
I wouldn't mourn it too much, just keep the Sigma 100-200mm F4.5 in mind as a future wishlist item, it is a rather nice feature to be able to select macro ratio at any arbitrary point in the range of the lens. +I love the solid feel of it, and the integrated lens hood looks badass while in use