Both schools are good. It all comes down on how much you
Want to spend, consider living expenses, travel costs.
As far as I am aware of, diamond flight academy is new but very well known for their high quality training, and their accom is near the airfield.
On the other hand Stapleford has a great reputation and experience, and its only 20 mins drive from your home but its more expensive than Diamond...
I would choose Stapleford if I were you