Note that the failure here was NOT the tool, but the user. Being my first build, I could see that eventually I could probably get competent with any of the three, but I could see that I was going to be pulling out and replacing frets (and possibly damaging a rosewood FB) before I was going to get the hang of them.
So...
I took a deep breath, and ordered one of the stupid-expensive Z-Files from Stewmac. And I do mean stupid expensive. I'm embarrassed that I paid that much money for a damn file!
Man, I gotta say, this is THE fret crowning tool for a newbie!!
I just finished my fourth fret job. I've done three builds and one re-fret, and on this current build I was able to go from bending and cutting the fret wire to installed, leveled, crowned & polished in about 3 hours. A significant factor in being able to do it so quickly is how fast the fret crowning goes with these Z-Files. They are almost foolproof, requiring just the usual care and attention that any tool use requires.
I'd love to see the cost figures for these things, because it's hard to avoid feeling that we're being, er, "taken advantage of" here, but the darn things really work great!