In reply to shaun walby:
> yer fine...the question was what do you use?
I was just pointing out that toothed or spiky cam devices are usually only used for top rope ("shunting " ) , often outside the manufacturers recommendations.
In a lead fall situation, they will probably break the rope.
Answering your question.
Personally for lone top roping, I have used Shunt, Basic/ handled Ascendeurs and Mini Traxion. Usually has worked out OK but have had the odd drama.
For roped lead soloing have used back looping, 7mm prussick, tied loops, modified Gri gri, Soloist, original Reverso, Silent Partner. Usually without any drama but usually a lot of frustration as getting the the rope balanced and running smoothly is an art I have not perfected. Hats off to Pete for getting this sorted and doing El Cap.