Hi
Yes I have used them before, when I had my last cleaning company in the UK. Highest one I had I had no problems with it was 30ft.
I am only 5ft 8" but I found that my past staff who tried to lift ladders etc found it harder than me, for instance I could easily move a double 18ft extended wooden ladder accross from window to window with ease, just good training and technique I suppose

So I am just looking for a new pole as my old supplier seems to have gone out of business.