Go FEDEX mate!
Seriously, I have never had a problem with them. They know their business inside and out... I made the mistake of trying to save some coin and sent my FLR (IED) via Royal Mail "Special Delivery" to the Home Office. My "Special" delivery is still in their system as "making its way through" even though my bank account has been credited and I have received the acknowledgement letter from them (H-O). What type of "Track and Trace" is that?
When you use FedEx, it gets scanned many times along its journey from truck to sort facility etc. They scan your pkg every day if say it is held at customs for any reason. My letters/documents have NEVER, I repeat NEVER been held at a border using FedEx. They in fact usually get PRE-CLEARED.
Anyway that's my 2 cents...
GT