One important thing to remember that the folks at Priority Pass customer service don't tell you when you sign up is that you can't upgrade in the middle of a membership year.

Say you sign up for the Standard membership ($99 + $27/entry, no free entries). If you change jobs, requiring a significantly higher amount of travel and need to upgrade to their Standard Plus membership ($249 + 10 entries + $27/entry after 10), you're just out of luck.

The refuse to accept, for example, the difference between $249 and $99 to upgrade. They also refuse to offer a pro-rated upgrade as well.

Not very accomodating in the current economic climate.