I've done a lot of research on this for the school where I work, wondering if it's best we go before we're pushed.
We've come to the conclusion there's nothing to be gained and plenty to be lost.
Financially, funding is no different now, although academies can set their own pay scales, but in reality that often means they pay more, not less for qualified teachers. They can appoint unqualified teachers more easily though and you'd be surprised how any staff in academies you think are teachers aren't.
There's a loss of autonomy if you join a MAT, which can be good when a struggling school is supported by a more successful one, but it does make everything less personal.
IMO the main benefit is for those leaders who get big payrises and a bigger empire. In secondary especially, MATs are often run by HTs with enormous egos IMHO My job in an academy of a similar size pays almost double what I'm on in an LA school, which obviously deprives other areas of the school budget.
We've decided that whilst there might be personal benefits for some of the senior staff, there's no benefit for the children.
I'll be interested to hear other views.