I have an old slx 22, which is fantastic, (but not good if you have dodgy elbows and cleaning over connies).
I then bought the extreme (i think the mk2) I broke the top 3 sections over the period of a few years (probably all my fault) but you need to be careful how you treat them. I now have the new exteme 22 (plus my previous extreme extensions 6&7) which I add on if needed.
Unfortunately i'm back to the dodgy elbows debate and i'm sort of stuck with using the extreme and being careful. The slx 22 I use as a backup and that's it. (it even has the old style clamps, which i've never had a single problem with...it's like an 'old friend').
So where am I at?
The slx is fantastic and if you're fit and doing basic house bashing then you can't go wrong.
The new extreme is very quick, very light and earns me more money every week (especially with these feet!) . But even when working normally, you can hear the odd slight cracking noise; I know it hasn't snapped but I'm just wondering how soon it will be before i'm paying out another 100 quid.
My verdict: Get the extreme and work slower, it'll still be quick and better for your body.