Welcome to the community!
In order for your phone to work on the Fido network it needs:
GSM, UMTS, HSPA and HSPA+ at 850 MHz and 1900 MHz.
To access LTE network, the phone must be compatible with:
Fido also uses band 12 (700 MHz) in some provinces.
The CAT S60 comes in two version the global and North America taken from here and the specs are:
|GSM / HSPA / LTE|
|2G bands||GSM 850 / 900 / 1800 / 1900 - SIM 1 & SIM 2 (dual-SIM model only)|
|3G bands||HSDPA 850 / 900 / 2100 - Global|
|HSDPA 850 / 1700(AWS) / 1900 - North America|
|4G bands||LTE band 1(2100), 3(1800), 7(2600), 8(900), 20(800) - Global|
|LTE band 2(1900), 4(1700/2100), 5(850), 7(2600), 12(700), 17(700) - North America|
Both phones will work on the 2g network, only the North American version will be fully compatible with the 3g and LTE network the Global version only has one compatible band for the 3g and LTE.
From my experience, Good network connection depends on 2 important things, your phone band coverage and Fido band avaliability. Overall you should have no issues to get a good LTE signal.
If you are a special case (like me) who uses a non Fido issued iphone 5S which does not have band 12 (700Mhz) but the block I lived in just upgraded to band 12. You will be stick in a position where the area around your home will only get 3G connection, in these cases the only real option is to upgrade your phone, and make sure your new phone supports the most common LTE bands in north ameraica.