Go for the latest. If you’re going to make a new character anyway, always go for the latest. The experimentals have always been very stable in my experience, and I’ve only found one build that was really broken, which was rapidly fixed. It wasn’t even unplayable, just about every liquid in the game spawned on the ground as a puddle instead of in a container. It made trying to keep hydrated tricky indeed.
I’d avoid updating versions then resuming a world, but that’s me… Speaking of which, on of my friends finally updated to 0.C or an experimental, from 0.A (what, two years of updates or something?). He seemed confused when everything was broken. I laughed, he cried about fishing json errors, it was great, he started a new world.
Edit:
Also, the latest experimental is always available off the main page at http://en.cataclysmdda.com/
It’s off to the right, under the stable releases.