I think that really depends on the camp you are in. Some people have complete faith in the $2 circuit that is attached to the battery being a reliable failsafe. I personally think the IMR is safer because it is a safe chemistry battery, not a LiIon battery with an overload protection circuit attached that could fail under a number of circumstances. I used the AW 2900 MAH protected batteries for a while and never had anything go wrong with them, but I feel safer with the IMR than with the protected cell because as we all know there is an inherent failure rate with any electronic device and that would include a protection circuit.
In my Katana, I use ONLY AW IMR the 18650 with a magnetic spacer in the long tube and the 18350 with the shorter tube. Same thing in my Hybrid Mini, Provari and SSGGTS. In my GLV3 mini I use AW rcr-123 protected's because that is what came with it when I purchased it from Great Lakes Vapor. With all the Genisis mods I own, the GLV is only used when I know the going may get really rough because even though it uses chinese attys, it is tough as nails and I won't get as upset if it gets dinged up like I would if one of my other mods got damaged
Frankly, the reputation of IMRs as completely safe is a bit of a fallacy. True, the manganese is "safe" chemistry in that, when shorted, the battery shouldn't vent flames. However, a short with no fuse is going to drastically heat up whatever is conducting it... The atomizer glows red hot with resistance in the circuit. A short heats up a
lot more.
Don't do this, but if you were to touch a copper wire to both terminals, it would quickly surpass 800°C (1500°F).
This was reported to be an IMR:
http://www.e-cigarette-forum.com/fo...ures-serious-battery-failure-imr-18650-a.html
Don't get me wrong, the IMR are great batteries, and in smaller sizes, the only ones that can really keep up with the demand we put on them in ecigs. However, there are posts all over with people thinking that IMR are completely risk free, and that's simply untrue.
As far as the scoop on batteries, IMR (a.k.a "high drain") batteries can output a lot more sustained current. Sustained current, however, is relative to battery capacity, so with bigger batteries such as the 18650, even the relatively cheap batteries have sufficient output. Note, however, that some of the protection circuits kick in around 2.5 amps, which means you're flirting with their cutoff point with less than around 1.7Ω. For 18650, I use the
AW Protected 18650 3100 mAh. They're not cheap, but are protected ICR with monster capacity (I charge mine for my provari every 2 days).
Here's another post I made with more details:
http://www.e-cigarette-forum.com/fo...5727-pictures-your-setup-123.html#post4960261
FWIW, I use
RTDVAPOR.com for most all of my battery needs (coupon ECF5 for 5% off).
I'm by no means the authority on the subject... there are some battery wizards in these forums that have gone into much greater detail.