Got friends who have children in both. Would say Rutherford House is more academic & has a more of a competitive edge. Some children do very well in the environment (I think progress is quite high) and other children struggle. Know someone who moved their child from Rutherford to Ravenstone because the child was really struggling with the pressure of feeling like she was always underperforming. However, that is not every child and most friends sing praises.
There is also a significant difference in outside space if that makes any difference to you.