My child is currently in Y8 at Sherfield and has been there since Y1. My honest advice is to think long and hard before considering sending your child there. It's not much cheaper than other, much more rounded, schools, the Senior Management team in Prep are rather weak, generally unsupportive of kids during critical times and are seemingly unable to tackle problems such as bullying effectively - this has been noted by parents of children in many year groups.
The sports facilities are poor and the results in core sports are weak. If your child competes to a reasonable level at an obscure sport, there is a good chance of obtaining a scholarship.
The school is run for a profit and despite the appointment of a new Head five years ago, there has been little investment in the academic or sporting side of the school, but significant investment in the revenue generating boarding facilities. Looking at the boarding side of the school, the overwhelming majority of boarders are Chinese students who are here to do their A Levels, which has led to great A Level pass marks.
Overall, I would say Sherfield is a good choice for a Pre-prep and Prep school, but there are much better choices locally for Senior education (Y9+). The academic side in the lower school is OK, but not outstanding. We, along with many others, are looking to move our child at the end of Y8.
On the positive side, the school has a very friendly atmosphere and the children are really quite molly-coddled. The current Headmaster is leaving June. He was significantly better than the previous but there will, naturally, be will be a period of instability as the new Head settles in.
If you do choose to go there, remember, they are a business so take the opportunity to negotiate the fees as they need more students to give the return to GEMS Group.