Have personal experience of Abel Smith and Millmead. Both are very good schools. Abel Smith has a new head, let's hope she can continue as successfully as her predecessor (s).
Abel Smith is a bit more "traditional", strict-ish uniform standards, number order etc for forms, semi-compulsory reading every night etc, Millmead (although this was a couple of years ago) seemed more free form less strict sartorially, no "compulsory" reading at home but a very strong encouragement to read (books on desks) any "down-time" reading is mandatory. Both have a very strong community feel, and very strong inclusive practices/policies etc. Feel free to ask about anything specific.