UKH

Is the blue Ice Choucas 3 harness buckle now considered safe? I’m interested in getting one for expedition use (Petzl altitude was uncomfortable) and just wondering if they have resolved the issues with the buckle on the previous version. 
 

does anyone use one/have any experience with it?

Yes, they changed the buckle to a threadback buckle, so it's safe as long as you remember to thread it back. The old version had a self-locking buckle that failed to lock in some circumstances.

I have the new version myself.

I have the single thread-back buckle version too. Its a great harness, ideal classical alpine/scrambling harness.