A while ago, I posted a question about this kind of glass, and Brian's posting convinced me to get one. Not only is it the cheapest Leica glass you can get, but also they seem to have their own... "quirks" (mine shows a particular kind of flare sometimes).
I read somewhere that this kind of lens was manufactured in large amounts. Besides, their being relatively slow when compared to other Leica staple-lenses probably turns the market on our favor. Since your Bessa has only framelines for 35, 50 and 75, you may want to consider one and get a separate viewfinder... although another strategy is to use the 50mm frame and simply imagine the covering angle as approximately half of that of the 50 frames. Or use the 75mm frame.
In any case, Joe, if you can lay your hands on one, don't hesitate. Just be aware of a couple of things:
The outer ring size is very small in many cases (36mm).
Some lenses are uncoated; great for b&w but not as great for color. Brian will tell you they may be a bit warm, but mine turned out the opposite.
The front of this lens turns as you focus.
The focusing ring can be a bit hard to handle (this depends on the lens shape). The fstop numbers can be the old-fashioned kind, not the usual f4, 5.6, 8, 11, 16 but something as weird as f4, 6.7, 9.5, 10.8 and the like.
On the bright side, you won't need an adapter! 🙂
Let us know what you get in the Leica forum about these lenses! 😉