I have had numerous failures with the Firewire product (both an early batch and one from last year). I have had 4 crashes with them...they test fine and then after non-deployment they test open, even though the "pyrogen" is still on the tip.
I've used a hundred or so of these without a failure, but I bought them after the intial batch which admittedly had problems. I also bought some during their pre-order sale last year... it took a LONG time to get them, I barely got them in time for LDRS in June.
We have them for a similar price, in stock. Hopefully I won't get in trouble for posting this. We have also seen no failures in the newest batches, the first run from several years ago had a chemical issue was my understanding.