I've done several OBWs. They are all 60 degree triangles. I have found that not blunting the corners works best for me. The difference between the OBW & 1000 pyramid construction is that the OBW quilt is assembled in diagonal strips, where the pyramid quilt is usually constructed in rows. If you have a design wall where your quilt is layed out, I would construct it in diagonal strips. Take the first full triangle that points up (from row 1). Take the one directly under it (row 2) and lay it exactly on top of the first, right sides together and sew your seam. Press the seam OPEN. Do not trim the ears. Put it back on the design wall to get the orientation correct. Now take the next one in row 2 place it on top of the previous one from row 2, matching all 3 points. Sew Seam, press... maybe a picture will help...
[ATTACH=CONFIG]433023[/ATTACH]