I work in an academy. It switched about 6 years ago.
We were persuaded (most staff were not keen) as it would mean we have lots more available funds to benefit the school. Were promised pay would not be affected, and conditions the same.
As an academy they can change the pay scales as they wish, change our working conditions so reduce holidays, increase hours, remove a lot of the safe guards teachers have which unions have fought for - our directed time restricts us to only one after school meeting a week, no meetings during our 'unpaid' lunchtimes, no duties during lunchtime and similar things.
An academy can reduce a teachers pay if they so wish - am sure many wouldn't stick around if that happened so doubt it would happen much! Also from a teachers point of view if I was to move to a new job I wouldn't necessarily have my experience reflected in my pay - with the LEA system your level moved with you. The grade I am on in my current job can be ignored by a new school and they can offer me a Newly Qualified salary even with years of experience!
Over the past 6 years there was some investment in the buildings- our business manager got a pay rise and our office staff seem to have increased a lot, we have a lot of improved sports facilities and paid for a big name football manager to come and open them!
However I am currently arguing for some responsibility money as I am running a whole GCSE course and not getting a penny for it to be told we don't have any money left.
We do have unqualified teachers teaching, and this seems to be creeping in more and more.
I am not convinced it is the best thing for students or teachers, students and parents may not see too many changes if all things carry on without issues - our parents would not be aware of our budget limitations currently - its just the staff who are feeling it.