Nightwatchman - the pension is good but the boarding school allowance is there to give kids stability instead of moving them every 2 years. It is the main reason that many stay in (me included) and the MoD knows it, it is the best retention measure that exists for those that want to take it up .
In real terms, I would have to earn another £50K to generate the £30K the MoD pays for my two kids to go to school. It's not everyone's cup of tea sending kids away to school and we only took up the allowance because of the poor local state schooling available here - just because I am serving doesn't mean my kids should be denied a decent education.
As Sven says - it is all the other crap that we have to put up with, which we would get paid extra for in civvystrasse, that balances the equation - FI, OOAs, ground tours, secondary duties etc etc. And we are not remunerated for extra qualifications - as an A2 QHI/IRE I don't get any extra dosh for the extra work or responsibility where a civilian equivalent would.