The only way is to read the announcements up top. "Updated Recommended builds". More stable bulds per dev. depends on the amount of users who test each devs. builds and confirm it to be "fine" or "have problems".
I thought Eko 12774 or BS 12874 are the recommended?
12774 is able to brick some routers compared to 12548. If I were you I'd keep track of the stats., and input from the majority who test new builds, before making a decision to upgrade to a different build. It took me about 6 months to make a decision to upgrade my WRT54GS V.6 from the dd-wrt Eko SVN11296 micro build to BS's 12966 build, however, I would have upgraded to an earlier build (w/ less knowledge of how stable they were) if it wasn't for the awesome support/feedback from the DD-WRT Gurus.