Dan,
I've never personally used an Anza knife, but started out making knives out of old files, and found they made(and still make) great knives. Only problem I had with the Anza's is I thougt they were rather pricy. There's a company called Sawmill Cutlery selling their file knives through Smokey Mountain Knifeworks catalogs that also look good, and are cheaper. Assumming everyone is actually using genuine file steel (W-2) they should all work. W-2 is a straight hi carbon tool steel, but has a touch of tungsten in it, which impoves its grain and abrasive resistance. Actually 1095 as also used by Nicholson for some of thier files also, but heck, we're actually gettin off the subject. I still use one of the early file knives I made, for my small game knife.