to the Op: 6" pipe cutters? anytime i've used 6" or larger i;ve used a gang saw ( gas powered chopsaw ) I too think youve got something out of wack here.
thouge there are big enough cutters to do the job of 6" its not worth the time invested.
I use a cutting wheel for finish work inside homes where i dont want the mess of saw shavings, but like the others on here I often cut pipe with a hacksaw, thats for no BS plumbers IMO
... I also am pretty fond of my M-18 milwuakee haczall.
To cydewater: I had the m-12 for a while, I found that the cuts were often not straight, and that like you mnentioned it would break smaller pieces. It worked okay for abs 1 1/2 but I cannot justify the tool as it goes through batteries and cuts fairly poorly even with a sharp blade, so it was sold.
M-12 impact driver is however the very best way ( again IMO ) to place a screw or secure an MJ and for 100 bucks comes woth the perfect drill to be an electric fitting brush.