What do you like?
Low/No Fee, and the ability to use the miles on any airline (preferbaly by converting to FF miles on that airline, not purchase a ticket from another source)
What don't you like?
Fees that don't make it worth using
What do you think of expiration policies?
I don't mind them as long as they are reasonable, say three years or something
What do you think of fees?
Would anybody say they want to pay as much in fees as they can? With cards like the CompuBank debit card offering you one mile per dollar spent with no annual fee you would have a hard time convincing me to pay a high fee for a similiar deal. (yes, I know that is debit card, but I usually prefer Debit cards)
What would you think about a dollar-based program (instead of arbitrary miles/points) where you could buy tickets at market value, anywhere and anytime?
I like miles I can convert to use as I want with programs I'm already a member of.