I have one son travelling to school 11 miles in one direction involving two trains and a 15 minute walk and the other two 13 miles in the opposite direction on a school bus. They all cope very well with their days. All three view the travelling part of their day as an extension of their social life and all of them have actually made new friends in this way.
Scary mum is absolutely right pointing out that they do start to go to bed later, leaving more time in the evenings for homework and activities. Do remember that they soon change from the fresh faced little year 7s into young men and women, and it all seems to happen very quickly.
All children are different but luckily mine have all adjusted to a long day and love their schools. Mine aren't the exception, lots of children seem to manage in the same way. If you think the schools you are considering are worth a bit of a journey, go for it I'd say. Good luck with your future choices.