I think they've scaled back the data they're providing on the service from 30 mins ahead to 15 mins ahead. Possibly as a result of the URL of the beta service leaking to far more "test" users than they were ready for, and getting too much traffic.

With the 356 being a once-every 20 minute bus during the day, and once-every 30 minutes at night, this means that at times there appear to be no 356's due at any given bus stop. The 356 appears to be working more-or-less as well as any other route on the site to me.