I'm about 100% leisure travel (the one time I travelled on business, it was made to be done via a corporate rate), so I figure its best to Priceline it - however, if I'm going somewhere on a MR or something, I'll stay at the cheapest place possible & get points. (I'll be staying at a Rodeway Inn in CMH, get the airline miles + the bonus for M.A.R. with NW, and its only 30/night) - however, if it's with multiple people (no family, just friends) I'll use priceline and if I can't get a cheap enough rate, I'll pay the extra 10 bucks to stay at a hotel that I like and earn the points (room is being split 3 or 4 ways, why not?) - so I guess its based on what my purpose is for the travel. Hotels don't have that great of reward programs, but I like knowing where I'm staying. On a MR, I'd rather be able to book a hotel that is near things (bars/movie theaters, etc) or that has free airport transportation and pay an extra few bucks than priceline something that will include additional costs, like taxi cabs or other transportation - also a "free" continental breakfast is great for MRs...
just my 2 cents...