If you do change to mechanical 2 blade I hear good things about the Rage and from experience I use the Gator XP.
Used the original Gator for years, the Gator XP is even better.
http://bowhunting.net/NewProducts/2004/Barry-GaterXP.html
I was going to link you to Bass Pro since the gator XP is a Bass Pro exclussive, but guess what...
They no longer carry it!
Looks like you can still order them from...
http://www.rockymtbroadheads.com/broadhead_order.html