I doubt that people really have TIME of day estimates - just day estimates
FedEx gives time estimates because they base their next day services prices off of when you want it to arrive. It's more expensive to have it guaranteed by early morning than mid afternoon.
Premier ships FedEx and Regular is UPS, correct me if im wrong. Also Fedex is overnight
My non-premier order shipped FedEx and is coming tomorrow (though it's progress seems to be pretty slow, probably because of the weather)