Pros
Great culture, flexible working, generous salaries and commission structure, genuinely offer a great work life balance, great south west London location.
Some people didn't work out because they wanted an easy ride, putting in minimal work and getting maximum reward. If you put in hard work (not talking about working loads of extra hours, I mean work hard during your 8 or so hour day) then you will get the maximum reward. The company isn't big enough to carry piggybackers than want to reap rewards of others hard work.
Joining Hanover was one of the best decisions I've made and would recommend it to anyone. I left due to making my next career step outside of agency, couldn't imagine working for another recruitment agency as it wouldn't be beaten.
Cons
Needs more growth, but other than that, as good an agency as you'll get, with down to earth people that aren't looking to stab you in the back