I too use PL for hotels only because I'm generally not time-flexible when it comes to flying. In dozens of PL bookings in the US and Europe I would say I was:

** Pleasantly surprised 30% of the time
** Accommodated pretty much as expected 60% of the time
** Not really happy 10% of the time

And the "not really happy" cases were as much my fault as Priceline's, because I bid on a 2.5* urban zone and got a crap property, or didn't look at biddingfortravel.com as closely as I should.

PL is great for when you're traveling alone and are not focused on amenities, room type, etc. It is not so great when you're traveling with family friends or colleagues and the kid really needs a swimming pool, you really need two queen beds instead of a king, etc.

I hardly ever bid less than 4* (never in Europe), I pay no attention to the automated rebid guidance from PL but run the median numbers from BFT or BB, and I never expect upgrades or extras from the property when I get there. I've saved many thousands of dollars. I once got a big project from a Chicago client because I flew in the night before the presentation and stayed at the Schaumburg Hyatt on a $29 PL rate. My client, the next day, couldn't believe it -- and asked me to show him how to pull that off. Got a great two-year relationship rolling. So I guess I owe PL for that too.