fireflybob,
Well, you have to land sometime....
Don't think I'm suitably qualified to comment in this context because the London Heli route is a little bit special in some respects, and there are things you can / cannot do there that can / cannot be done elsewhere.
Also, if we're talking 500ft altitude then there are additional rules that apply over built up areas (1,000 feet above the highest fixed obstacle within a horizontal radius of 600 metres of the aircraft) ... but again, London Heli may change things.
Someone will doubtless be along shortly to fill in the gaps I've left !