Leki trigger S vs. Trigger 1

Trigger 1 is a bit easier to click in and out of (especially since they made the button better a few years ago) Trigger S does not have problems with snow and ice accumulating in the cavity (not as serious a problem as some make it out to be imho) because it is a nylon loop. Trigger S gives you a bit more up and down flexibility in where you grasp the pole and there is a nice selection of leki gloves that work with it. I have no idea if one or the other does a better job of releasing in cases where it is necessary.

Ultimately I think the fact that Leki looked like it was going to replace the original trigger system with trigger S across it's line but then kept it and named it "trigger 1" gives you  a sense that many people did not think that trigger S was an improvement.

Here's a thread I fired up on the topic a while back when the S first came out... http://www.epicski.com/forum/thread/63874/new-leki-system-sucks

These days I tend not to use straps for daily skiing - so I'm not too worried about the issue 

I have both types . Like 'em both equally. Use normal gloves (spyder) with ad hoc strap for each.

Trigger (or Trigger 1) straps tend to come accidentally out a bit easily than Trigger S, but have observed ice accumulation into the mechanism, as said already. Plus when using the poles to push oneself, it's easy to unvillingly unlock it...

Both things don't happen with the "S"

I've put a larger basket in the base trigger poles (which are a mixed alu and carbon model) and use 'em in off piste situation (and keep these poles always in the car's boot, even in the summer, handy to use for a trek...) and use the "S" (which are full  carbon ones) on groomed trails...