I've used both the ratchet and pin axle stands. The ratchets are handier as I can get more accurate heights that with the pin. Never had a problem. If you look at the design of the ratchet, each grove of the ratchet is machined slightly inwards. As such, the stand needs to come-up BEFORE the release mechanism can be applied. As such, there's no real concern about it failing.
More often, when I've see axle stands fail, it's because they are not used correctly, as in they are no on level ground, or incorrectly balanced.
FWIW - get a proper set. For piece if mind, I always, chuck some other extra support under the car (wood, wheels, etc)