Switch from SMF 2.x with 10k+ visitors daily... features...

I have read the FAQ, but curious still.

I am thinking of changing from SMF 2.x to XF.
I am hitting 12k visitors daily on an active site (ctguntalk.com).
If I convert to phbb then to XF, will it convert the groups, does it have subscriptions built in?
How are the Mods for it? Any portals yet?