Not me but I thought it might be an interesting discussion topic... maybe that's a stretch :p
I like to keep an eye on what's happening locally and I noticed with one large accountants near me, well they are top 100 so to me they are large, they have an intermediate parent company who are "abc" Chartered Accountants but for their lower level/not so profitable work they use a subsidiary which is not affiliated to any accountancy body.
I guess this makes them more competitive at the lower end, by lower end I mean the bulk of work that most sole practitioners do including myself. There doesn't seem to be any real downsides either as most think that the subsidiary is the same as the intermediate parent company. None of their clients seem to realise any difference.