In reply to Simon Caldwell:
We decided it was too complicated:
Once you get onto fixed length poles then they've got to be the right length for each individual (give or take - as you say, you can move your hand up and down), so adjustable ones are clearly a bit more versatile in that your mate can use yours or whatever.
With fixed length you're more likely to need to move your hand up and down the pole, as you do (and which I personally prefer to do in any case). But for anyone who likes using straps this freedom isn't possible, and that does limit the range of the pole to the one length.
The same pole at different fixed lengths is going to weigh different amounts, making direct comparisons that bit harder.
Not all manufacturers offer a suitable collapsible fixed length model anyway.
We'd agree the widget or clip is a point of potential failure, but in our experience it doesn't happen that often. We'd probably be just as likely to snap a pole, in the long run!