I built the CLC MillCreek with 1/4" luan. In shopping around, I learned there are huge differences between what different stores sell. Not only in luan, but in all their woods. Case point, the luan sold here by the Home Depot is cheap ($8 a sheet) and excellent. The stuff sold by Lows I wouldn't use for making shoeboxes. Cardboard would probably be stronger.

There definately is a weight issue. The issue with that issue is is it an issue to you. My MillCreek is overweight, as per the spec sheet. I don't care either. It's rock strong, and I can handle the heft, so I'm satisfied. A person trying to build ultralight would not be.

You also may want to click on this link, and see what this fella has to say about his building a motor skiff out of luan.

Remember, if you really want it, you can rationalize it by saying its mahagony.