Well, collectively between all my Chansey buddies (some of whom are now Blisseys), I’ve racked up almost 900 km. That doesn’t go very far in terms of candy, though. I still don’t have a fully powered up Blissey… but I do have 5 Blisseys, which I deemed was more important for the gym scene. Hatches are really the way to go for easy candies, and I’ve been reasonably lucky in that department compared to others. I’ve also racked up quite a few Snorlax miles, which was a good choice since I don’t run into them in the wild very much (but I’ve never acquired a good IV Snorlax, so my power-ups aren’t all that impressive and can’t sit in gyms any longer), and a bunch of Lapras miles. My latest Chansey buddy has 425 miles on it. I’m not sure if that is my highest total for a single pokemon, or not.