What about a scimitar +1, keen, vorpal, "the enchantment that makes it hit as if it was +5", flaming, frost, shocking!! Or a Brilliant Energy, Keen, +5 scimitar. That would check crit very often hehe.
Just kidding. I think Improved Crit is a great feat. It is a good boooster for lower level fighters and give them the theat every so often punching hard with the weapon. From an RPG perspective..... yes just hold on..... It signifies further mastery with your weapon, that you really understand how to use your weapon and make it hurt.
I build my characters fro mthe perspective of what fits with my story for them, not what makes their numbers better. Well most of the time.