Here's my take- You can get 5 nights at some REALLY NICE hotels for 28000 points. If you make your reservations early enough, for the right times, that can be worth $400 a night, or $2000. Compare that to the $350 value of a FF ticket, plus the 8000 miles you would get, and I think using the 28,000 starwood points for a hotel stay crushes the FF conversion. This is particulalrly true if you fly a lot and you get plent of FF tickets. Starpoints seem to be harder to earn, given that they don't have a 1000 point internet booking bonus (yet???) and other such point bonuses that airlines sometimes toss out.