In Canada, EMS is now handled by Canada Post ... so at least the delivery behaviour is the same as for SAL. If the postie calls while I'm out, s/he leaves a slip and I pick the parcel up at the local sub-post office - which, fortunately, is close to home!
One thing though, orders that are shipped via EMS are likelier to be held up by Canada Customs. Perhaps the logic is that courier service = more valuable = more worthy of close scrutiny? When items are shipped via SAL, there seems to be little or no slowdown whatsoever. So in terms of speed, SAL can be as quick as EMS - and considerably less expensive, of course.
Incidentally, my all-time record was a ten-week-long wait in the hands of Customs - after which they sent the parcel back to Japan!
The order was for used kimono, and Customs sent me a letter explaining that the items had been rejected because they hadn't been marked with clothing labels in English or French indicating country of origin*, as required under NAFTA. I looked up the Customs Act, phoned the inspector in charge, and pointed out that used/vintage clothing from non-NAFTA countries - such as the kimono in the shipment - are exempt from this requirement. On the second attempt to ship, there was no problem! I was really peeved, though, that Customs hadn't contacted me before returning the shipment. It wasn't the Japanese seller's fault [he was apologetic over the whole mess, but of course it wasn't anything he was at all responsible for!], so I ended up covering the shipping cost twice. A learning experience, I guess...
The moral of this story is: if you ever decide to import used Japanese clothing to Canada, and you anticipate any problems, drop me a line and I'll tell you which chapter and verse of the Customs Act your Japanese seller should quote on the accompanying documentation
*As it happens, kimono and other traditional Japanese garments almost never have labels, not even Japanese ones.