Yes the MIA is a tough cookie and MIC even tougher as the stuff like nav assessments are set at a much higher level than basic MLs
Plus you have to log a minimum of 40 multipitch mountain/seacliff routes (of VS or above)before you go for assessment, they actually recommend 60.
If you are starting from scratch that is a big ask, I was lucky that I had over 300 mountain routes mostly in the E grades up to E5 under my belt before I started even my ML
The bit I found hard was getting the teaching days in and organising belays for clients.
I came across a few folks who were operating at VS the minimum level and thought they always seemed to be at a disadvantage, so would reccommend get your grades up into the Eees and go and bag the mega classic routes on places like Cloggy, you cannot beat having a strong log book.
Even for summer ML what the assessors like is a logbook with folks doing big classic walks in different areas Wales, Lakes, Peak District and scotland, scotland, scotland plus you get bonus points for winter stuff.
One other point when you present yur logbook put some impressive photos in, works wonders!!!!!!!