I have never used Hotwire or Priceline for flights. I always use hotwire or priceline for Hotels and Cars. Note: If you use hotwire or priceline to book a known flight (i.e. like through a
travel agent), then they are fine.
If you use hotwire/priceline with unknown flights/bidding, then you have to be prepared to have really inconvenient flights and connections. If you are a college student coming home for the summer and wasting a day is not a problem, then go for it. But, if you are paying $1,000/person to go to Disney (including air, room, tickets, food, etc.), then saving $50, but loosing possibley 2 days (arrive late, leave early), seems penny wise, but pound foolish.
I paid a few extra $'s (about $100/person) so I could take a 7am non-stop flight that arrives at 11 (Disney around 1pm), and return on a 7pm non-stop flight that arrives home at 9pm. That give a leisurly arrival and departure day. We even have time for dinner reservations.
Otherwise, I might have to take a 3pm arriving at 7pm, and get to Disney around 9pm., and might have to take a 11am flight home. That basically kills the arrival and departure days. Worse yet, I would probably get connecting flights that take 5+ hours travel vs. 2.5 hours non-stop.
Note: I actually bought the airline tickets through priceline. They have a price match guarantee (if anyone books the same flights for cheaper, I get a refund), and I didn't have to pay a travel agent fee.