Even after getting to be pretty good filing freehand, I converted to the 2-in-1 and have been using it exclusively for 5 or 6 yrs. or more (can't remember when I started). I have several, one Pferd (7/32 file) and 2 Stihl models (13/64 and whatever size I have for my 346xp saw with .325 chain). Yes, it seems they can be tricky. I sometimes have to use pliers to spin a file, or remove it and re-insert. Regardless, it's a great tool. I've had neighbors, colleagues on the fire dept, that I've handed a saw to use while on a community job, who cannot get over how sharp and fast cutting my saws are. (Granted, most of these guys are weekend warrior type, not pro sawyers, but all the same . . . )
Because we are in a pine forest, all conifer wood, when sharpening for our native trees I usually put a more aggressive angle on my saw teeth, and take an additional swipe or two with a flat file off the rakers. Regardless, the 2-in-1 is my go-to. I got rid of the grinder I had after it gathered dust for a number of years.
The thought just occurred to me--has anyone tried a dab of penetrating oil on the file to lube it inside the 2-in-1? (Myself, I haven't used wd-40 in years, I prefer Kroil.)