I'm going to remain neutral on these changes until I see how they work out in practice. It doesn't look like SDC is functionally any different if you already had it free as an elite benefit, but I'm not 100% certain from the wording. If SDC is restricted at all, or availability somehow decreases, that would be a pretty big value hit for me. SDC is pretty much the only benefit that has actually influenced me to purchase a ticket from United as opposed to Alaska.