I also am silver with US (from a comp) and their automated process seams to be non-existant. NW's process is very smooth. In fact a few months ago they changed the policy and the agents can no longer upgrade you over the phone. NW was the first company to come out with an automatic upgrade system and has been using it for years. Once in awhile it has a hicup, but 99% of the time it is flawless. Your best bet is to check in on-line at the 36 hour mark and see if anything is available. When you go to check in it will ask you if you want an upgrade. If one is available and you have not already been upgraded the system will upgrade you and let you know in seconds. If one is not available it will put you at the top of the list at the airport. Once you check in though, EUA will skip your reservation, so you take a chance if you are not upgraded and continue to check in that if it runs at 24 hours out it will miss you. However, the flip side to checking in early is that if they don't release the last few seats till at the gate than you are at the top of the list.