Hey I'm a DL Silver and am fine with my minuscule upgrade percentage. However, I'm traveling JFK-SEA this summer on an flat-bed configured 767 and I was wondering if I should upgrade my wife and I with miles (traveling on a K fare). However, if you'll pardon my ignorance, I don't really know how to go about this, whether I'm likely to be successful, etc. Do people still upgrade using miles domestically? Will this jump me in the line over higher medallion levels? Help please!