Oh dear, more Elstree bashing. I learnt to fly there some time ago, and have continued to hire from their well maintained fleet. The instructors are enthusiatic and very professional, the brand new Warriors/Archers are a joy to fly, though the twins (Cougars) are a bit tatty as there are no new build a/c available.
The AFIS has never been rude to me, though I have heard and seen pilots been fairly reprimanded, usually because they are unaware, not having properly self-briefed before arrival/departure, of the particular requirements for Taxiing/landing there.
It is a demanding environment and given a disciplined approach will certainly stand you in good stead for visiting other airfields (Shoreham springs to mind).
I omitted to say that it was Cabair I was referring to, and highly recommend their expertise.