Ah, once again the rumour mill turns. 
I don't know where you get your information from, but once you
go operational and prove that you're not a complete screwup,
nobody's going to get on your case if you're a corporal. The
chickensh*t harrassment is left at the Hendon gates.
You can indicate all you want, it's not going to make a jot of
difference. My interview:
Serious-looking sergeant: You want to go to Commandos?
Me: Do I have a choice?
Serious-looking sergeant: No.
Me: So what the f*ck are you asking me for?
That didn't work - a week later I got my letter telling me I was
going to Hendon Camp. I found out over the next two and a half
years that my attitude was exactly what they were looking for. The
best laid plans of mice and men ever so often simply go balls up.

You heard wrong. If I have a brother my parents would have some
serious explaining to do. 
Of course they're underpaid - they're NS men, aren't they?
Look, for a couple of years at least, the job's an absolute gas but
there are much easier ways of making a buck.