MAXQDA probably has the most equivalence between its MAC and Windows versions. ATLAS.ti is pretty much equivalent with regard to coding and basic searching, but it does not yet offer more complex searches on the MAC.
What specific features do you need in order to Framework analysis?
I've just come up against the same issue. I think that my best option may be to use the Windows version of Nvivo on my Mac using VMware, which I have anyway (my institution has own-use licences for mac and Windows versions). There is a pedigree for the Nvivo version from the UK NatCen that is useful.
I do find Nvivo non-intuitive tho', so I'd be interested in any other solutions that you have found.