I have a 42 ft unger - 7 sections I think - it came with my trolley system from peter fogwill.
Generally, I use it as a 3 section or 4 section pole and this is what I generally take with me. It is fine at this level.
As a 4 section I can just reach a 3 storey block of flats with the thinnest section half extended. For me, any higher and it would be too whippy.
Except for doing the attic rooflight on my own house which takes six sections I have never used the 5,6,7 sections and I find it so ungainly and whippy that if I needed to use more than the fourth section with any regularity I would investigate a different type of pole.
I never extend the thinnest section beyond a foot or so normally and would rather add the fourth section to maintain rigidity.
It's a cheap pole, and I've used mine for 18 months and replace the cone inserts every few months.