I've only caught the 3 thus far. I ended up with some 11+ Santa Hat variations, evolved 2 into Raichu.
Hopefully they enable trading, and some of these duplicates I have I can offload. Would really hope they do international trading, these Regional ones are horrible, in that, unless you legitimately travel, you can't get them. but then there's the spoofers everywhere putting them on gyms all over the place!
I still don't know what's rare or not in Gen 2. Apparently Togetic is? I evolved mine after hatching two Topegi's, and then walking to get the candy, as the rest of the baby evolutions (what the turn into) can be caught in the wild and/or hatched.
Was shattered, Wifey and I caught a Pineco, funnily enough, it was under a Pine Tree!! But then I hatched one from a 10km egg?!?!!? Seemed like quite the waste, unsure on rarity, being 10km egg?