It depends entirely on the circumstances.
Some areas (e.g. Bristol) have an appalling LEA that's suffered from years of local politics, crap staff and classic civil servant sloppiness. Most primary schools are now academies and for good reason - increased budgets, increased accountability and its gone on to be shown in better academic standards. It's enabled schools to operate independently like businesses and bring genuine change quickly. They've also been able to flush out more of the bad staff.
Want a good example? In one school I worked in around 2005, we paid £850+VAT for an outside tap that should have been a £150 job because we had to use a particular supplier. That doesn't happen anymore, the academies shop around.
That said, allowing a bad pilot to captain an a large budget can lead to an academy going very wrong. Plenty of schools haven't planned well and ended up essentially going bust when the writing was on the wall for a long time. Others have become strange religious pressure pots that breed unhappy children or simply extremism.
There are some bad stories but plenty of genuinely amazing ones, especially with some of the 'free' schools that have been created since 2010.
TL;DR
There's no 'right' or 'wrong' answer to 'academisation' in general, it all depends on the school and the LEA. My feelings from my experience though is it's superb for bringing genuine change. It's all down to leadership.