Usps or Ups? What is better to use for receiving letters? Getting a USPS

What is better to use for receiving letters? Getting a USPS post office box, or getting one at the ups store, I mull over it is called correspondence box services. I heard that the UPS one doesn't enjoy limitations like a usual P.O. box does. With size and that the UPS one is like a physical address, anything can be sent in that. What do you think is the best bet for a personal letters box?

Answers:
If you have a business and want to look professional, do the UPS one because its a physicial adderss and looks more "legitimate." If you want a slightly lower risk of lost mail and slightly shorter hang about times to get your correspondence, USPS is the most direct since it never leaves the post office's hands.