I buy a lot of upgrades for cash. They can be a good option but you need to research the route to figure out how full the flight will be (generally as well of specific date, and days of the week). (Check seat availability immediately before flight for a couple of weeks). If the flight is regularly fully booked up front..... don't hold your breath for a purchased upgrade.

You don't get bonus miles on an upgrades.

Ambien is better than Xanax. My strategy is go for the UG and if it doesn't clear (<3% of a a lot of flights) go for the Ambien.

Cash upgrades are almost always a lot cheaper than buying business outright.

Status has no impact on cash upgrades (only for mileage and GPU upgrades).

Lufthansa and Swiss business class sux. They are all sliders or recliners.

Almost all UA are now lie flat (comfortable but a little crowded on the 777 unless you have an empty seat next to you ....then you have a bed and a seat).