I would weather use a battery that will "fail safe" instead of a battery that could under the perfect conditions emit fire, or deadly gas. If something goes wrong with my aw imr batteries, the spring will collapse like it did before, causing the battery to lose contact with the mod, causing the battery not to drain any more. What if something does go wrong with the circuit on a protected battery, the chemistry in that battery can cause bodily harm.
I would weather replace a $70 mod, then have anything happen to my person from a battery that can catch on fire, or emit gasses that are deadly. In the thread on this forum that talks about batteries, that has been linked to on the previous pages, it says that these problems have happened to the people moderating the forum, and concludes that at this time the SAFEST TYPE OF BATTERY THAT IS FOR SALE CURRENTLY IS THE AW IMR LINE.
I would wrather replace a battery, and mod any day, then have fire, and/or deadly gasses. Wouldn't you? If there is a short in the mod, of caused from an atty, or caused from a conector, the spring will collapse from the heat. That is a safety feature, it is built in to your mod, by you. It might not have been built there intentiouly, but you did build that safety feature into your mod. Thank you. Had that not happened before to my mod, then yes the battery would have continued to have gotten hotter, up to and possibly including melting the mod. If the circuit fails to stop a protected battery from doing the same thing, you could also have a fire from the battery to deal with. That is why I will always use a safe chemistry battery in all of my mods.
That is the safest type of battery made today, maybe tomorrow there will be another option out there, but so far that is the best we have.