I've had this turned on for a long time, as it's really useful. What FF program you bank the miles into should have no affect- it just has to be a CO operated flight, I believe. I've gotten a new page when my gate changed after the initial page was sent, but haven't gotten delay notes. Most of my delays have been under an hour, they might send a note if it's longer.

I like it, it's a handy service for me. I get the email a few days before with my trip summary. Then 24 hours before, click the checkin link & print my BP. Flying from SEA, the gate is usually not on the BP at that point. Usually get to the airport as the 2 hr page arrives with the gate, so I zip through security and head off without having to track down one of the gate info monitors. Easy easy. ^