Dos anyone use this thing? I'd heard it does a real bang-up job in getting the lead out of a bore.

I have a S&W 52 & the wadcutters have a nasty habit of leaving a bit of lead behind from time to time & I prefer a pristine bore as the Marine Corps taught me.

Any thoughts?

I have both a 2 and a 3, both work very well on both lead and copper.  But it takes along time, like 8-12 hours for really coppered bore.

Copper really hasn't been a problem for me, only the softer .38WC in my 52.

What's the difference between the 2 & 3 versions?

the 3 is more compact, it comes with a 1 piece rod (I use the 1 of the 3 piece rod on from the Foul Out 2 for pistols).  Until you try it on either coppering or fouling you'll never know how really dirty the tube is.  Often you cannot see coppered or all but major leading (much easier to tell).  Also there is allot of carbon under that fouling.  I tube can be so clean that patches appear to be come out with solvent only.  But clean it with a foul out and after you remove the metal fouling.  Reclean the tube and you will be taking tons of carbon out of it.