I keep forgetting to rebuff it every now and then, and I always end up running around with a huge DPS loss because the only thing that shows me if I'm buffed is the weapon glow, which is covered 90% of the time by spells mobs and all the special effects on the screen.
And no, I don't wanna "cast it every 30-60 seconds after every fight" and bla bla bla. The buff lasts for 5 MINUTES!!! I shouldn't have to recast it every minute to prevent myself from forgetting to do it cause I wasn't starring at my Wizard's sword to make sure it still had a glow or not.
Watching the bottom of my screen and not notice my buff icon is a lot easier to keep track of a buff than having to watch a little weapon glow which becomes confusing if my weapon already has a glow of it's own.