It was very enjoyable, although obviously not as good as a SSIW bootcamp. There wasn't a no English rule, but almost everything was in Welsh. There were lots of activities, including a quiz on Friday evening, a walk with the Aberteifi group, meals out and entertainment/singing in a local pub. Also craft activities and a programme of short talks about Cymdeithas yr Iaith campaigns.
I think the actual mix of activities depends on where the weekend is taking place. (I heard reports that the one in Bethesda wasn't so good - it depends on the accommodation and organisation).