A handsome canoe is always pictured with the catalog blurb about this bit. Since you don’t really know a bit until you’ve tried it, I tried one. It’s unlikely I’ll ever make a canoe, but the bits are truly useful.
Any coopered or staved construction is simplified with this style of bit. There’s no need to calculate the angle between adjoining strips in a particular construction. You just rout an adjustable flute-and-bead joint. One edge of each strip is fluted (or coved, if you prefer), and the other gets a matching bead. Put two strips together, edge-to-edge, and you have a tight joint that can be adjusted almost 45° in either direction.
This is a good way to assemble wooden hot tubs, planters, barrels, coopered doors or bowed tops for chests.
Usually you see two-bit sets for this application, and in just one size that forms a 1/8"-radius flute/bead. While you can mill stock about 1/2" thick with those sets — producing a kind of tongue-and-groove edge joint — the radius limits you to 1/4"-thick stock for real staved constructions.
Rockler’s innovation is to put both the flute and bead profiles on one shank. To switch from one profile to the other, you only have to raise or lower the bit, not change from one bit to another. In addition, four different sizes are available.