I've never used one, but my neighbour has one and it seems a bit of an expensive faff to be honest - I have a squeegee attachment for my Wolf Garten kit and it does the job just fine, and allows me to reach the upstairs windows
Yes I have one, works ok, never had any problems with it, it's very useful for cleaning up spilt liquids on hard surfaces & for removing condensation from your windows too.
@Jiffy , I got one primarily for removing condensation, it's great for that purpose, 1 pass & job done, clears a pane in seconds.
I have some window spray, a microfiber cloth and a cotton tea towel. Does the job beautifully. And I can clean the mirrors with that kit too. Mossiac