Thought I'd reply as an unsuccessful, yet hopeful, applicant:
1) Applied twice, fell short on entrance exam (GAMSAT) both times
2) GAMSAT: 53 (first application), 58/59 (second application (actually sat the exam twice scored 58 in March and 58/59 in September)). No A-levels (arts student so have a BTEC), BA 2.2. Work experience - 4hrs p/w care work since Nov 2013, 4hrs p/w volunteering at local hospital Jan 2014 - May 2015. 7 days shadowing doctors August 2014. Full-time HCA since May 2015 - present (quit my marketing full time marketing job).
3) Currently doing a Masters to help boost my application as with a 2.2 it's incredibly difficult. Fortunately I am track for a merit which opens up some more options for my application this year and the course is almost finished \o/ . However, doing a full-time Masters and working full-time has been pretty strenuous and required many social sacrifices, but I suppose GEM won't be much different haha. Also I am trying to arrange some more shadowing with some of the doctors from the hospital I work at, which will hopefully be this summer some time.