ABS started with a cable pull handle in the 80's, and went to the charge handle to pressure pierce the nitro can for reliability. Ran into inconsistencies with cable stretch and moisture freeze up in early models. FWIW. With nitro, they maintain bag pressure better at varying altitudes (it is N and outside air mixed), and with a sealed can, less susceptible to moisture issues. They also went with two bags independent of each other and not one, venturi helps here, also. One will still float you, they say. But, two systems to fail instead of one. Their pitch, not mine.
With that said, any bag is a huge step above no bag, and keeping it maintained, thawed every day, etc., goes a long way to saving your butt. They all have tradeoffs. Buy what fits and works for you, practice with it, and maintain it. When you see the video tests on the mountain with dummies and triggered slides, these are pretty amazing devices. Float theory works. Nothing protects you from trees, rocks, sled, other victims.
