I've used ovens fairly extensively on a couple of live-aboard sailboats. Lots of baking especially (easy to carry flour; hard to carry bread!). In both cases they were propane powered. I'm partial to the Force 10 (a "real" boat stove/oven). I haven't used or researched the one you linked to. I would just want to make sure it has the safety features that a designed-for-boat unit has.
On the other hand, as much as I enjoyed baking on the "big" boats (and would really have missed a true oven), I would not likely put one on the 22. For me it's just too much of a space trade-off, plus the heat in nice weather.
On the other (other) hand, I *would* consider something like a Coleman camping oven (obviously not when underway). They are essentially a collapsible metal box that sits on a regular stove burner and make an oven (which, after all, is just a glorified metal box). I have not used one, but know plenty of folks who have, and they are pretty good for making muffins, etc. Then pack down flat and stow away easily.
Another option (I must be up to the fourth hand by now

) that folks use to good effect on smaller sailboats that don't have the room to spare for an oven is to "bake" in a pressure cooker. You essentially just use it as a heavy pan/oven. Bread and that sort of thing come out just fine, even though it's not exactly the same as an oven. Side bonus is that things are fairly contained due to the pressure cooker's clamped lid (so if you have good pot clamps, you can use this underway, whereas that would not work with the Coleman oven)
For baking on the C-Dory I'd go with one of the latter two options. They could also potentially be used ashore for more flexibility. But, if an oven were a big priority for me, I'd have one, in the form of a Force 10 with a full on, ABYC compliant propane setup. Because, hey, the boat is for pleasure, and so if an oven brings it, then why not.