Comparing fret files/fretting hammers?

[devilfish]

Hi,

I'm undecided on which fret file to buy.. I've tried the double sides diamond file that's identical to stew mac's and I'm not in love! has anyone tried the 3-in-1 file on stewmac? What are people's opinion.

Also fretting hammers. Nylon heads or brass heads? Interested to see which people prefer?