One handed fortify ENCHANTMENTS and POTIONS do not effect daggers - oddly enough, potions of fortify archery do.
Also I have tested it quite a bit and I'm positive dual flurry does not affect dagger. The dagger power attack combo doesn't seem to change noticably, while dual swords with the perk pull off the move in a flash.
Wait you serious? *curses like an injured sailor*
No wonder fighting with dagger was such a pain in the [censored]. I gave up on them and switched back to swords for regular fighting and only using daggers for sneak kills. Good the know the reason as to why my dagger was doing such crap damage when it wasn't a sneak attack
*annoyed ninja cat is very annoyed.*