Hello 123. Another Wellington family here with a very positive experience of the school. My advice to you though would be to choose a school that is easy to get to. You'd be surprised how often you will be there, seeing plays, watching matches, having drinks with the parents. Is there a fast motorway/a reliable train line that connects you easily and quickly? Even termly boarding requires more of you than you think (according to my god-daughter's mother!). Make sure the location works for you logistically.
Anyway, just fyi, a quick snapshot of our collective experience of Wellington (our son joined in 2017 as a weekly boarder).
Firstly, and perhaps mostly importantly, the pastoral care is excellent. The school boasts a lovely, kind, warm teaching body who are very approachable, and the communication structures are easy to understand. We have been rather pleasantly surprised by it, tbh, having suspect it might be a rather austere environment. We chose the school because of its academic record. We have a very bright boy and since we live pretty locally figured if boarding didn't work out we could always switch him to a day place. Our son wouldn't dream of it now. He absolutely loves the school, loves the evenings with his friends, and is a fully signed-up card-carrying member of the Wellingtonian community. He lives and breathes its ethos much to our surprise (mindfulness, sleep hygiene, Harkness etc).
There are some very rich and famous families at the school, but actually, in our experience, the run-of-the-mill folk like us are really lovely and down to earth (and some of the rich and famous ones too!). The ones who turn up to the school's social events are very straightforward people, lots of whom are working hard to put their kids through a school that they love.
Sport: rugby is taken very seriously at the school, but it's not the only currency. My son played rugby at his prep but not to any particularly high standard. He has chosen to play a new sport and loves it. It's much less competitive, but it's given him huge amounts of confidence and enabled him to be 'sporty' in his own way. I do think if you had a child who didn't like sport at all, they might struggle at Wellington. Sport is compulsory.
Drugs: we've had no worries there yet (as far as I know!). The school's impressed us though with how openly it talks about all those things, so it's definitely an ongoing conversation. The Deputy Head has also made it very clear on a few occasions that these are expellable offences. I suspect any misdemeanours are taking place at weekends (at home!), when quite frankly it's the parents' job to step in and police the situation. I think it's more of a London problem than a school problem, IYKWIM.
But I think - one year in - we've been most impressed by how well our son is being prepared for the future. Julian Thomas is a hugely impressive headteacher, who thinks very deeply about what education should be and how it should change to meet the needs of adults hitting the workforce in 8-10 years time.
Good luck with your decision. I think instinct plays a big part, so do trust your heart whenever you engage with the schoolchildren and the teachers at your various choices. If you do decide on W, don't hesitate to drop me a DM if you need any further info re: houses etc.