Faendal has used stupid armor for me on occasion...yeah, Faendal, it gives you a few more health points, but you know, yours regenerate really quickly, anyway, and the other set has nearly double the armor rating. So...hello? He did use the bow I gave him, though (well, once I remembered to give him arrows, ahem)--the one from a certain quest that looks freaking awesome.
Quest source:
Spoiler The dude who teleports during the battle.
Magicka-reducing bow. Not useful on most things we encounter, but truly gorgeous. He finally ran down the charge, which I didn't think they could do, and took to using the elven I made.