Using miles for domestic upgrade online
I too am trying to use miles (25,000) RT for a domestic trip. I first looked at NWA.com because the routing (SAN-DTW) is on NWA metal. NWA.com gives you the option of clicking on using miles for upgrade. I then went to Delta.com and tried to find the same option. I was making myself crazy trying to find it. I called the Medallion line for some help to located such a link and was advised that I can use miles to upgrade on K fares or higher, depending on availability but, the option of doing it yourself is not available online, like it is on NWA. They said just call us first to make sure its available then either book it yourself and call back for the upgrade with miles or, since I am a Gold Medallion, they would do the whole thing for me over the phone without a service charge. That's what I did, but wondered why the Delta.com site would not offer such an option to just do it yourself. Turns out I was able to get a Q class and use 25,000 miles for the RT upgrade.
I would think they would offer such an option so the customers don't have to keep calling and tying up agents that could be servicing other customer needs. Just my opinion. Thought I would share my experience.
Happy Holidays everyone.