I still don't trust Hotwire's 4* to be the same level as Priceline's 4*. Thus, I would use Priceline and bid. And you'll likely still undercut that $97 for 4* from Hotwire anyway. Would not recommend 3* anything in SF; 3* in most large cities are far too variable for my taste.
This is interesting CrazyOne, because I actually have an opposite perception when it comes to Hotwire star ratings to Priceline. I guess I tend to put Hotwire's scale a notch higer since all the amenities of the property in question are listed and if a 'customer favorite,' then a sampling of customer comments could also be obtained.
I agree with you regarding Priceline's 3 star offerings. Just too variable, for me as well, that's why I try to limit my biddings on either 4 or 5 star properties as much as possible to guarantee a great deal. So Fliar, I think that 4 star at Embarcadero is pretty good deal. It might be the Omni or the Hyatt Regency. I think the Park Hyatt (my favorite) is .5 star higher. Good luck.