4G is still the most common type of mobile broadband connection but it has comparatively slower speeds than most normal broadband packages. This would make it difficult to do high-data activities like running certain applications or streaming media
Coverage is dependent on the mobile phone reception in your area, so the mobile blackspots that have you cursing your provider might also affect your mobile broadband connection
Unlike home broadband connections, mobile broadband usually has monthly data limits
Overseas charges have come down, but it's still not cheap to use a dongle abroad