I don't know why so many people are complaining about their SWU. Surely, if you fly enough to be PM or DM with Delta, I would hope/expect that you also understand the importance of reading the T&C's before choosing your gift selection. The SWU T&C on Delta's website is one of the few things that are actually quite clear and well written (well, at least on DL or KL flight, on AF, it's a bit tricker ).

With that said, we've been happily choosing SWUs for the past however many years... Well, it all started when NW gave them out to their PE in the old time. Paying less than 3K a ticket for Europe - Hawaii in business and domestic first confirmed at booking isn't that bad of a deal, imo. Or a trip at about 1,700 USD in business from Europe - US east coast. Or even using them on AF could be good deals too. Of course, with upgrades, you have to be more flexible in order to get upgradable (Z for DL flights) seats at time of booking which I've always managed (well, I only get M if I can manage running the upgrade through at time of booking).