DD was really torn. She had to choose as her secondary only went up to GCSEs in any case. She looked at lots of options, both state and private. She eventually whittled it down to two choices - one, a state school with a sixth form and the other the local FE college.
Pros of the FE college were that it was a 10 min walk from our house, and dd was really attracted to the more adult environment. Cons were that dd didn't really feel that they were catering to very academic students like herself. She was unimpressed with what they emphasised at the open day and didn't feel confident that they would give her much relevant support with the university applications process.
Pros of the school were that it seemed to be targeting students more like dd, with specific help for those aiming for medicine which is what dd wants to do. Cons were that it was a pain to get to and dd was really concerned that it might irritate her to be in a school environment where they were still overly fussy about dress code etc. She didn't want to be treated like a kid any more!
Eventually she chose the school and it has been brilliant for her. We have a lift share to get her there and back and there are buses if needed. Turns out that the environment was much more chilled than she expected, they are treated like adults and the school doesn't really enforce the dress code. The help for university stuff has been excellent. And the unexpected bonus for dd is that the social life has been amazing and far better than what her friends have experienced in the local college - there is a real sense of community in the school sixth form with lots of socialising across all subjects, whereas her friends who went to the college only tend to socialise with people on their courses because they only come and go for their timetabled lessons. And despite doing maths and science herself, dd tends to like socialising with arty, creative types!
DD has also benefitted unexpectedly from being in a school environment with younger kids. She trained as a peer mediator for example, and has really enjoyed helping younger kids to resolve their disputes. She has also enjoyed getting involved with school productions etc, which wouldn't have been an option at the college.