I thought that was a neat idea, but I didn't feel a need to buy a sled like that to try it out. So I build my own. The picture at left shows the sled having just been used to cut the side off a piece of crabapple lumber that I cut off one of the trees in my yard when I pruned it.
The guy at the wood show was also selling extra wide resaw blades, and riser blocks for 14" bandsaws. Certainly, a resaw blade is a good idea for this application, as the saw blade will often pull a little towards one side or the other. A wide blade, with lots of tension reduces this tendency, as does cutting slower. So use the widest blade that you have if you try this technique.
Its not really possible to move the log side to side in a precise fashion with this jig. But really, all you need is two flat faces, and you don't need a jig to make the remaining cuts. So after cutting one side off, rotate the log 90 degrees, make another cut, and then make the rest of the cuts with a regular fence.