Alltec Advance 600 is what I have and it's great.
Had it up to four flights, though not by choice
Actually, I had it to 13 storeys, but that was with the help of a lift.........
When working high just use longer hose through a window on the floor on which you're working. A remote plug and job done.
I have recently loaned it out to a CC who had a six week old Ninja that was buggered. Ashby's made hime drive down to them rather than recommend anyone locally. This was an 8 hour round trip. I did have a problem a couple of years back (self inflicted). I called Alltec and they recommended someone local which no doubt saved me a small fortune.
He loved the Alltec, he did mention the weight but in five + years this hasn't caused me one problem.