On the other hand... I have 3 of the originals with integrated battery; one of them is more than 2 yrs old, and the other 2 are almost 2 yrs old... and all still work as well as the day they arrived. The +2 yr old one met a violent fall onto concrete, and never missed a lick, still works like a champ.
I have one more of the originals, which I bought used from someone at VU, and it's a tiny bit iffy; sometimes it seems to not work, won't fire, and I can't figure out why; when I get it home, suddenly it's working fine. No idea what conditions it faced, before I bought it from a user here.
Andria