I loved this bed and started building it last summer. Most of my lumber was inexpensive (meaning somewhat warped with dings, knots, cracking, etc). Since I wanted a very clean and smooth look, I took a lot of time filling, sanding, filling, sanding, over and over in order to get it just right. I also like the paneling look on other beds I have seen, so I added 1x over each of the panel board seams.
For the frame, I built using 2x4 and then ran MDF strips across. With all of this wood, it is a very heavy and very sturdy (if we ever move, my wife says we are leaving it at the house).