I never have a problem with either UPS or FedEx. But then again most everything I order comes through UPS. FedEx only when I order something from LL Bean, even then I don't pay for shipping.
In fact, aside from video games, I don't pay shipping for 90% of stuff I buy. I always buy enough to get free shipping. =D
So, with that in mind, I really don't have much room to complain if something get delayed a day or so because I am getting, more or less, so to speak, what I pay for. Which is nothing really. But UPS is very good, 2-3 days and I usually get it more likely in 1 -2 days.
Also, if yo get to know your normal delivery person, they just might get things to you earlier instead of letting them sit at the warehouse until the delivery date.