No way I'm taking a downgrade from F to C (esp. to Y) unless it's a short leg on a much longer trip. I'll wait for the next flight. If UA says, "tough", your F from SFO-FRA is now C or Y and it won't get better on a later flight, even if it tosses some miles at me, I'm looking for a new plan. I save my miles for F. I don't even understand why anyone (MR or not) who maintains status and accrues miles would even redeem for a Y, unless it were an emergency. I understand "stuff" happens, but if it turns out to be bait & switch stuff, goodbye.