I know my situation doesn't apply to the OP's issue but I'll share it anyway.
I ordered a 536 from Scanner Master on the 8th of this month, and it was shipped out same day. They only offer Canadians USPS regular or USPS express. Not sure why UPS isn't an option. The package was in New York by the 10th and across the border by the 11th into Toronto where it sat for customs inspection.
A tidbit that some international shippers/receivers may not know: the USPS tracking number can be plugged into both the USPS tracking form and the Canada Post tracking form to get updates. Typically, when it's in the opposite country (Canada in the case of the USPS, and USA in case of Canada Post), all you get is the high points, like "package mailed in originating country", "package departing originating country for Canada", etc. This is what I saw when the package was in USPS's hands.
When it got released from Canada customs into Canada Post's grip, updates on the Canadian side stopped. This is not normal behavior - normally the updates continue right on into my mailbox. On the USPS site, I even got "package arrived in destination city", and then "delivery attempt made - held for pickup". But it wasn't at my post office at that point, and Canada Post's website said that "this package does not qualify for tracking information". Calling Canada Post wouldn't help, either, because if you're not the shipper, they don't care about you. Scanner Master would have had to initiate a trace to find the item, not me.
I kept diligently checking with the post office and eventually found the item on the 19th, five days after the USPS tracking said a delivery attempt had been made. There was no indication of why it was delayed or for what reason. The customs documents state it hadn't been opened, so it's not like it was held up there. It may have gotten misplaced on a truck or in a back room. The radio was in new condition, so it wasn't like it got taken out and played with (which I've had happen with other products I've sent thru the mail before).
I place 100% of the blame on Canada Post on this one, and it's another reason I wish vendors would consider allowing for courier services to all destinations. If I'm willing to spend the extra $ to have it shipped UPS, and you clearly have a UPS account already, I don't understand what the downside is.