Eric, I'm no expert, but I've at least had the opportunity to do both kinds of panel joints. CLC and Pygmy have a kind of raging debate between them about which is best (CLC uses scarfs, and Pygmy uses butts). Having built kits from both companies, my experience is that joining the scarfs, when the wood is pre-scarfed (as in the CLC kits), is less time-consuming, perhaps even a bit easier. Plus I like not having the added layer of fiberglass there. But the butt-joints on the Pygmy actually were "fairer." Not a bit of flatness to them. There is hint of a flat spot in the scarf joints on the CLC. There are pros and cons to each. But both work. It may be a matter of personal preference.