No issues whatsoever, having had many items (including valuables) over several years delivered by this carrier..
From my experience, the United States Postal Service (USPS) has been ultra reliable
Bear in mind, that (USPS) First Class Mail International has no tracking if that's important to you, but as I said, I have had no issues over several years..
If you want (online) tracking ability, (USPS) Priority Mail International offers this facility, but at increased cost..
Delivery time on average is about the same.. 7 - 10 days, sometimes more, sometimes less