If you want your package to get there slower than walking it, then yeah you can use USPS. Honestly I do everything I can to not use them at this point.
USPS priority has been amazingly predictable for me all year, even through all the pre-election noise. I think they were 19 for 20 in being on-time to their estimate (including several of Saturday mail, Monday deliveries 600-900 miles away). The 1 that missed missed by a day.
I have had had some terrible parcel post experiences, but priority has been good.
I've had 5 packages this year take longer than two weeks priority. One not of those five was 40 minutes away that took 8 days to arrive. I've had stuff sit in post offices so long I had to call to make sure they weren't lost. Another item get marked delivered in a different zip code than my own, only when I opened a case was the package thrown on the ground in front of our mail box cluster. I can't tell you how many packages marked as delivered only to be delivered the next day.
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