Thanks for the thoughtful comments.
So to clarify:
DS has already received an offer from each school.
I now get the point about the importance of House Masters (thank you) and will meet them later this month at Eton (already done that at Harrow - been allocated what we believe could be a brilliant House Master and great fit for our DS).
Replying to the comment about how can a person get this far into the process without knowing about the schools, not sure if you've been through this process or not, but it's not at all easy to know much about a school after a one hour tour from a boy who's given up his time (and is keen to get back to his own stuff) to give you a tour round the place. Not sure if you know, but you don't just rock up at Eton admissions office and say, 'O.K chaps, let's get a second, third, fourth or even fifth tour round the place (like a poster wrote about Winchester on another thread). We were very much made to feel fortunate that a boy was taking his time to show us round what he thought were the important parts of the school, for about an hour, once during this process. That's it at Eton - about an hour to decide if you like it or not and like peteneras says, most people spending the thick end of £250k would take more than an hour to find out about their purchase. At Harrow, there was a more considered approach. For example, during the test, Eton admissions said, 'Thank you for dropping your son off. He'll be ready to collect at x time'. At Harrow, they said, 'You've all probably had a long journey to get here and you're welcome to help yourself to a coffee, here's the wifi code. You're welcome to stay here and catch up on e-mails/work. Feel free to join Mrs X and take have another guided tour of the school where you can ask her as many questions as you like, or walk around the school grounds (here's a map) on your own.
We felt like Harrow was as much a club than a school, with Old Harrovians looking out for each other in later life (work experience e.t.c). Is that the case (or not). If so, does Eton have what we've perceived to be this kind of old boys network. Also, that is a great point about the overseas reach. Reputation is one thing. Current activity is another. For example, can anyone elaborate on the deal with Harrow's presence in China?
Head Master at DS prep said although Eton is bigger, the houses are much smaller (50 boys at Eton 'v' 70 at Harrow). Is that of any relevance (or not)?
In the meantime, there's no family pressure either way. We all just want DS to be happy and to have the best opportunities (which if those are leavers destinations is really only Eton). I have met some really impressive Etonians and some not so (meaning, they are not all charismatic leaders). The Harrovians I know are all charismatic too, and they are all exceptionally considerate and polished gentlemen. Interestingly, in the particular environment I have met these guys in, the Harrovians work for the Etonian. Is that the usual expectation?
DS is academic (but not a scholar), sporty (in all prep first teams), musical (grade 4, 5 & 6) on two instruments and singing. He's not the alpha ale type, is quite considered in his approach and fiercely independent. Has been boarding since 7 years old and is pretty ruthless when deciding on what activities he'll get involved in (or drop).
Please forgive my original post. It was late at night, and one of those days.