Originally Posted by jhpark
Last I looked into it, premium awards were treated as Y class for upgrade purposes, so you could use E-upgrades at any point in time. No need to wait for the window.
This is correct. No need to worry about e-upgrades though since all US elites get unlimited domestic upgrades. The premium awards are very nice because they are pretty much F tickets but you can get onto any flight with Y availability. I booked DTW-CLT-SRQ-CLT-DTW this morning for travel Easter weekend using a premium award. After a quick call to the CP line was confirmed in F on 3 of the 4 segments. The ticket would have cost about $950 so I figure that to be a good use of 50,000 miles.