I have used SLX22 and SLX 25 Extreme.
I much prefer the closed length of the 22. That's about it in favour of the SLX22.
However, the weight difference is very noticeable to me. And I'm one of the idiots who dares to put an Aquadapter on the top too.
I much prefer using the Extreme 25.
The halfway or fully extended positioning of the Extreme took a little to get used to, as in a week.
Now I find it's actually quicker as it's a choice of halfway or fully open, as opposed to infinite choice.
It is quicker to extend.