I would still say that I open hand most things - when I catch a hold dynamically, it's always open handed and mostly I'll hang off it and pull to the next hold keeping it that way...
Recently though I've noticed that my thumb is naturally coming into play on crimps - where my hand would be completely open and my thumb and little finger not gripping the rock - now I'm naturally pulling with all 4 fingers and my thumb and it hasn't been a concious decision -
It's simply happened on it's own -
Which I think is a good thing - I'm not pushing the 'crimp' situation - it's just developing itself, like my fingers know what to do!!
Furthermore when my thumb finds it's way into play on a small crimp I feel so much more solid and far more able to strongly pull through on the next move -
I've been told a number of times, most recently by Squib - that full finger strength takes 2 years to develop and not to push it.
7 months after I wondered about crimping, it's nice to see that it's not an unnatural product of 'practicing' it specifically - it's simply a natural product of one's development as a climber.
Maybe in another 7 months I'll be holding edges in the full crimp position, but I'm going to leave that decision up to my hands... they seem to know what they're doing!!