They give us an option to go live in multiple currencies which were not supported by any other system we used before them, it's really helpful when you have customers with different currency and payment methods like Paypal or Amazon Payments as well - I don't think there are many systems out here that offer this feature! The support department takes time to understand your requirement but once they do then everything works wonders.
It has been 2 years since we moved from our old platform so may be some things haven't worked perfectly yet but all issues get resolved pretty quick if reported promptly. Currency conversion was one of the major pain points of integrating the new solution into my existing site because i couldn't integrate paypal payments easily without making more workarounds compared to what competitors could do very quickly.