Well that also depends on where those carriers are. The Samsung Galaxy S3 for LTE in North America has a dual core processor and caters to specific LTE bands/frequencies. I bought my GS3 in India which has no LTE but has HSPA+ and uses the Quad Core chip. They also have an LTE version for European use. So its not only Blackberry, but Blackberry does usually seem to have more tailored variants for each market.
I am planning to get rid of my GS3 and try to get a AWS compatible variant from Canada, and even the one without AWS (1700) support will work, as not many places outside Canada use this band. Either of the two versions available in Canada will work practically worldwide once unlocked, as most providers worldwide utilise the 2100 frequency, and even Wind Mobile does 2100 in addition to 1700, so service would be provided.
Check the following data file for info on worldwide providers...
http://connectedlife.gsma.com/wp-con...ngdecember.pdf