I see Ballistol referenced quite often here and on many firearm forums.
My experience: Ballistol is an OK product and quite handy to have around.
IMO, though, it is not a miracle, one-step gun-care product nor even a "best" one. Excepting one particular use, I no longer choose it for my firearms.
My main beef with Ballistol is that contrary to manufacturer's statements and at least one popular story -- "The contents of the 60-year-old can were still in perfect shape and still worked!" -- it will gum up over time, in my experience a matter of months. Hence, it's not a mainline firearm item for me.
Why do I think it will gum up? Two reasons:
(1) I've seen it. I used to keep a 6-oz aerosol can, spraying straw inserted, on my bench. It was there in that condition for a year or more. There is a small divot, depression or ring below the spray button. Over time, I saw the over-run product gum up and accumulate in that area. It was right there in front of my eyes. You could lift out some of the stuff with a pick or a Q-tip and put it between your fingers. It was gummy.
That was a bummer, as I'd really come to like Ballistol for a quick clean and lube of any given gun. Now, I won't put it on a gun that's going to be put up in the safe for any period.
(2) On Ballistol's own site, in the FAQs, they advise that if you have the liquid (non-aersol) cans to not store them with the sprayer cap in but to remove the sprayer cap and seal 'em back 'em with the red cap. Color me a skeptic, but what I'd seen with my own eyes combined with this advice makes me believe Ballistol does not age well when exposed to air. And my guns ain't airtight.
Now, I do still keep a little (1.5 ounce) aerosol can in my range bags. It's the perfect size for traveling about, and Ballistol has worked very well for me as a one-product clean-and-lube for immediate use. I've field stripped, cleaned and relubed .22s and shotguns at youth shoots where we had hundreds of kids participating, and it put the guns right in straight order.
It's also a nice general product for a sportsman to have. Cleans up leather decently (let it sit over night to lose that smell, though) and you can wipe off wood products -- such as the handle of Buck 110 -- with it.
I still keep a can of it (red cap on, no sprayer) in the utility closet and have a little 3-ounce bottle of liquid (well-capped) on my bench for certain light cleaning work. But I no longer use it as a mainline gun cleaner, lube or protectant.
I returned to G96 for that purpose. I'm speaking of the G96 Complete Gun Treatment (aerosol) and the G96 Gun Oil (liquid). When it comes to gun metals, it works as a light to medium cleaner and light lube and actually is an excellent protectant. It doesn't gum up, and it's got an excellent range re operating temps. I've hunted shotguns down to -20 with G96 as the only lube. To me, it also smells pleasant, whereas I've learned to tolerate the smell of Ballistol but do not like it.
Don't get me wrong, I don't think G96 is some sort of miracle. I keep on my bench and use FP-10 solely as a liquid lube with the migration property that I desire. I also keep syringes of two types of grease, Lubpriplate SFL-0 for about 90 percent of the applications I need and Shooter's Choice All Weather High Tech Gun Grease for when I want something a bit heavier, tackier.
