Using PL for flights used to be a great bargain when they had bonus money available which would widen the difference between a winning bid and the lowest available airfare. Nowadays, that gap is so small that it really is not worth (IMO) giving up control of which airline you get, not getting miles/points, flight times, and desired connections (or lack thereof). I was lucky enough to get a couple of round trip flights from BOS to DCA for less than $70 total back in the good old days, but those days probably won't be coming back anytime soon.