R10 will ship SAL if you ask them too. In fact, I never got the impression they prefer EMS over SAL.
Anyway, EMS is fast and trackable, but it costs a lot. Also, you can get insurance for it.
SAL will typically take 3 weeks or so, and it's not trackable, but it's cheaper. I don't think you can insure SAL packages.
Me, I always use SAL when buying from HLJ or R10. If I wanted something really badly and can't wait, I'll buy from a US retailer.
Most recently purchased: MG Hyper Mode God Gundam
Most recently finished: SD Verde Buster
Supposedly working on: HG Exia + Astraea