The first thing you need to know is that Emanuel guillotines its registrations list, and as the schools is increasingly popular (as an active first choice, not just the fallback it was several years ago) the lists are closing earlier each year. The list for 11+ entry 2017 has already closed (last year for 2016 it closed in March/April, the previous for 2015 ie the current year 7 it closed in July, but before that it didn't close until about October/November if at all).
So if you think you might be interested, register.
The 10+ entry has doubled in size (from 20ish to 40ish ie 1 to two forms), which has led to a reduction in available places at 11+.
It has a very generous sibling policy. Siblings only have to reach the basic pass mark, and can even have a resist. It offers a lot of scholarships (art, drama, music, sport) and those chosen for awards only need to pass as well.
Knock on effect is that the remaining places for first DC into the school are fewer in number, and the competitive pass mark needed to be towards the top of that group is rising. The school does however say it attaches importance to the interview (every candidate is interviewed, which is one of the reasons they say they have to guillotine the list) and are looking for pupils who bring something to the life of the school rather than just the ability to pass exams well. Not quite sure what this means in practice!
Go and have a look. The open days are a bit of a scrum, but you should get some feel for what the school is like.