I just wanted to unreservedly apologise again to you all for putting such crass and unnecessary comments earlier in this thread. It was not at all helpful, and I can completely understand the offence these caused - sorry.
We put our DS name down at E and H when he was six years old, after visiting a prep school that seemed surprised we had not already registered anywhere. We only registered at those schools because their facilities were not like anything available locally and we wanted our DS to be at a boys boarding senior school (so choice was relatively limited). It was nothing to do with status (as suggested earlier my AP).
After he started at his current school, the guys from Wincoll came and spoke to prospective parents, we visited and were blown away by the beauty of it and registered him. Everyone we met was really helpful and understated.
Meanwhile, and being factual, the problem we have is that our DS would suit any of the three schools, even though we had no idea about that when we first registered. He's very musical (grade five+ on three instruments), he's not a scholar (but still pretty bright), he loves sport and is in the school's first teams, but is not at county standard.
Thank you all for all your kind help and sorry again for the way I wrote such appalling comments earlier.
We're really struggling here and have now decided to take the advice of OP and leave the decision for now, but thank you for all your helpful comments and please accept my sincere apologies for any upset I caused. To a certain extent, we're still in limbo as DS does now currently know the result of his final test, interview at E and is one of 250 that will find out next week. Presumably, if he's offered a place, we'll get to ask as many questions as we like and can make our minds up from there.