DD is only a term and a bit in (switched for year 3) but certainly no regrets so far - she is having a great time. I moved her mainly because I saw how bored and underchallenged her brother had been when he was in year 5 and 6 at the same school, and thought I might as well move her at year 3 which is when the biggest intake is.
The new school, which is officially selective, though I don't think turns that many children away at the junior level, does seems more academically challenging, though she still says the maths is boring and easy (even though the year is split into two rough ability groups). They have homework (about 10-20 minutes most nights) and spelling tests, which I am neutral about, but she seems to actively like.
They have a more structured timetable, and have history, geography, science and PSHE etc as separate lessons, whereas at her old school there was just one big project or topic per term. There is some coordination across the subjects though, eg doing Greeks in history and making Greek masks or vases in art.
The biggest difference so far is in the amount of sport - and actual competitive sport against other schools, even in year 3 - which she loves. PE at her old school always seemed rather half-hearted, and I don't think she ever got at all sweaty, but she now spends an afternoon a week being very active, plus PE and dance on other days. I hated team sports, but she thinks hockey is the best thing ever. 
There is also a huge range of other optional activities for their Friday afternoons - options like fencing, sewing, judo, forest school, origami, glee club, latin for older ones etc.
The school day is longer by about half an hour, but they seem to pack an awful lot more in.