USPS delays
I ship almost exclusively with USPS priority mail. Has been pretty good, with the occasional longer ship time.
All of the shippers have issues. Just depends if it's your package for a turn in the barrel.
My latest favorite with USPS was a box from Cali to Maryland. It got to the distribution center near Maryland, then returned to me because the box was incorrect. Not their fault, but I wish they would have caught it when I dropped it off.