Schoolmum77 glad you had a chance to visit both W & T again. Makes all the difference in making that all important decision. It's funny how you view schools from the initial open day visit compared to when you receive the offers. It's at this point you really start to think of all the different questions which are now relevant and you look at the schools in a very different way.
We were in the same position as you, we liked both W & T went with DS after offers for another visit. For us we wanted to know more about the Senco department and pastoral care. That made a hugh difference, but even after all that we chose W, it was always W for our DS, and we always knew that.
If your DS is undecided and likes both, then I would go on everything else, class period lengths are slightly different - at W each period is 45mins each, at T I think they're 30mins each but somebody at T may be able to confirm this.
The whole logistics, distance, is one much more closer to home? Reason being is when you factor in after school activities and then getting home the shorter the distance the better. Though at W many come from far a field but come GCSE time, time does matter. Boys who are on sports scholarships have to play away games, extra training on top of homework it's quite hard to keep up.
I think in your heart you probably have a preference, and I hope that it's the same as your DS. Both are excellent schools but I know it's not easy making that choice. I do feel for you and many others in your position. All the best!