Groundhog's right!
There is nothing to beat being up close and personal to the gutter. Of course that means ladders, so if you are happy with ladders then don't waste your money.
However, if you want commercial work then ladders will most likely be a no no. Likewise are you willing to climb on three storey work?
Vacs do the job, not spotlessly but they will clear the rubbish out and leave you with clean hands and no broken limbs.
So as a kind of life insurance then I suppose they are worth it, the same reason people use the waterfed pole system really.