I routed out 1/4". Honestly, not a big deal... if you have the router, it's easy. Get some boards to act as "stops" for the body of the router, clamp 'em in place, be VERY precise about the depth you set, and after that it's just moving the thing around until the MDF is erased.
The bat handles ARE too short without routing, imho. You could use a hammer/chisel, but if you have the router and are comfortable using it, I think it's a better choice; nicer edges and flat area.
-->VPutz