Slightly off topic but consider looking at the Shindaiwa Multi as well.
I have 2 of the power heads and most of the attachments and I have nothing but praise for mine.
I love the short shaft prune saw, it and the top handle saw does most of the work!
I am thinking of getting another hedger attachment and modifying it by making it a stubby shaft like the short prune saw attachment.
I have petrol hand held hedgers as well but in my old age they are getting heavier.
As for long pole hedgers I find that an aluminium adjustable trestle or an adjustable platform ladder (mine goes from 5ft to 8ft platform height) beats holding the weight of extended hedgers and gives you a better top line, most of the hedges around here are lelandii cypress I wish they were pittosporum or crotons.