I have tried all three and this is what I think.

I currently have been waiting two weeks on items to arrive from the States using United States Postal Service (USPS). Their online tracking system is horrible / archaic, with the only message appearing on their website being "your item has been accepted", meaning that the sender successfully gave them the package to send. Apparently you don’t hear anything else until package arrives at your door. I won’t use this service again. I will insist to senders never to use this service again in sending parcels to me.

UPS tracking system was excellent, however their staff are rude and incompetent as is FedEx's. So make sure you fill out the labels/documents completely (and I mean completely) and take your time doing so, and don’t be pressured and take short cuts at the behest of their lazy counter staff who couldn’t care less if your watch is received or not. I suggest including the end users phone numbers, as often the parcel gets stuck somewhere and customs/courier company will need to get in touch. For example I had a situation that the courier company wouldn’t deliver as they needed the end users Social Security Number for customs purposes, and I hadn't included their contact details. Also make sure you know the end country's "harmonized codes" so that the customs department will be able to categorize your item for taxes and duties. Harmonized codes that I use most often include from Australia to the US include:

910221 Other wrist watches With automatic winding
910229 Other wrist watches, Not Automatic Winding

The only other point of note concerns insurance, which i believe has been covered in posts prior to mine. I won’t bother mentioning quality packaging, as this is a given....

Unfortunately you have to choose to best of a bad bunch…unless you are super wealthy and have the time to deliver/ or pick up the watch in person :)

Regards
Eyal