camalot protection

Question
How big of a difference is there(safety wise) inbetween the newer cams with a wire loop vs the old cams with a solid bar?

Answer
By safety, I'm assuming you are referring to holding strength.

In my opinion, the greater factor impacting the holding strength is the quality of your placements, quality of the rock, and the manufacturer's force rating.  The benefit of a flexible stem cam is just that, it can flex to a certain extent, where a fixed stem cam will not.  However, from what I've read, fixed stem cams used to be placed in shallow, horizontal cracks and then a runner was tied to the stem as close to the rock as possible to reduce torque and therefore reduced force on the stem.  If you were to use a flexible stem cam in this scenario, the stem, and runner would hang far away from the rock creating additional forces.

If you're interested in learning more, the How to Rock Climb series is a great set of references, as is Mountaineering: Freedom Of the Hills.

Hope this has answered your question.

Nick