ya i went with a deWALT extendable blade, works perfectly fine. However this open cell styrofoam is god aweful, my project is halted until i find some of the pink or blue closed cell ones.
I prefer to use an X-Acto kit. I have several types of blades for mine. That and a regular old kitchen knife. The drywall type sanding block with a angle helps to smooth out tight places too.
