My fear would be that my notes are being erased when putting the notebook into my backpack.
Wipebook (http://www.wipebook.com) did a short video comparing correctable vs. dry-erase vs. non-permanent pens:
https://m.youtube.com/watch?v=m-hE6VDAG_I
It demonstrates their resilience to accidental erasure.
The 4x8 sheets of melamine backer board is cheap, cheap, cheap! Where I currently work, we have 80 linear feet of the stuff on our walls in our dev area (held up with nails and construction adhesive). It isn't fancy, but my employer believes more in results than being "impressive" (plus, we don't get any clients back here anyhow).