I have been using 8 inch "Handy Files" since my apprenticeship in 1973 and they are probably the files I use more often than any other in my somewhat large collection of metal working files. I don't know for sure, but maybe Stanley was the first one to make these files and then other file making companies copied them? I have used ones made by Stanley, Nicholsen and Simonds and can't say I have found much difference in any of them.
I don't remember where I learned this, but I took the tip that with new Handy Files, I use them ONLY on softer materials or metal till they dull for that use, then use them on harder materials. IOW, I buy a new one just use on wood/plastic. When it dulls, I use it on aluminum then brass. When it dulls for that, I use it on steel. (However, there have been a few times I needed a sharp file for precision work on steel, so went with a new one just for that job.) What you don't want to do is file a lot on steel with a Handy File and then expect it to be sharp for brass or especially wood.
I make sheaths for my Handy Files out of cardboard wrapped around them and masking tape wrapped around the cardboard. Then using a Magic Marker, I mark those sheaths "Wood," "Aluminum," "Brass" and "Steel." As they dull for each use, I just move them to the next sheath.
Gus