UKH

I'm wondering at what condition folk replace their picks? Or how you decide? Interested to read different approaches /mindsets on this.

I have a set of 'best' picks that go out on ice only (I'm kidding -that just means I picked spares and haven't used them yet ). And the set on my axes are maybe 15mm or so shorter than when new after 3 years belting rock on mid-grades.

I picked up a decent condition OEM used pick and was surprised to find it had been made a lot narrower (top to bottom looked at side-on) -maybe 60% of the depth of the nominally same pick I'm using. Such a variation would make quite a difference on ice, but at least it encouraged me to re-profile more aggressively when I want to. 

Yes I try to keep a best set for Ice, though last year and a good section of this has very much killed of the best part! After that the criteria for changing them is price and availability! For sure it won't be this season, even if there getting to the stage of needing significant re-profiling for any water ice. Next criteria would how motivated can I get for another Scottish winter to warrant the expense! 

Yup- I think price & availability clinches it for me too. I did 'use up' a Terra hammer in the eighties though -to the point it was just too sore on the knuckles to use with the shortened pick. Today's offset shafts make that less of an issue and filing in new teeth as necessary seems to make replacement more 'optional'.  

I wonder which tools have the longest picks to start with?

I tend to let them go past the third tooth then change. For mixed I don't even bother tapering the tips anymore and they last a fair bit longer, just file then every so often to get the shape.

For ice I've got dedicated picks which only get used on water ice and have been lasting very well. The cheap(ish) Polish picks have helped quite a bit up keep the expense down on having multiple sets.