Learned a few things recently that hopefully will help others. Item 2 is probably the most important. 1. Using GPUs is frustrating (most know this, but this was my first attempt). LEARNING: don't go out of your way to book a W fare or higher. If its what they are selling already, fine. Otherwise, it may not be worth the extra money unless you can confirm immediately (again, recognize that others already know this). 2. Using GPUs for a family is frustrating. It seems that if you have more than 1 or 2 on a reservation, you will be skipped every time inventory is released because united only seems to release 1 or 2 seats at a time. LEARNING: book no more than 1 or 2 on a reservation. This is a lot of work, especially with children because you have to call to get E+ seats, plead for the baggage benefit, have them link the records to avoid unaccompanied minor scenario, etc. that would happen by default if on a ticket with an elite member. 3. Trying to split a reservation is impossible if multiple carriers are involved. Yep, this also is frustrating. (Learned this during the process as I saw we were getting skipped or upgrades. If united splits the reservation, the other carrier is likely to see it as a cancelled ticket). Hope it helps another family. We went from 8 seats available to 3 in the past few days, just a few seats at a time. Yes, I recognize a few more seats could have been sold (can't guarantee these were upgrades), but the above applies regardless from how the agents shared the process works. If their I formation was incorrect, would be happy to e corrected as it would make my travel planning much easier. My biggest frustration (though I don't see how united could do it differently easily) is that it is like people can cut in line. If the next in line needs 4 seats, I wish united could recognize that and not release any until 4 are available (or at the airport when it is obvious they won't have 4 left to release). Instead, they release 1 or 2 and the party of 4 gets skipped so thy person 5 or 6 in the upgrade list gets the seat. Repeat that a few times and the family of 4 will never clear.