What are the problems associated with renting a “European” or “Worldwide” pocket WiFi?

Cost and Performance
All other rental hotspot options that allow you to access the internet in multiple countries are based upon roaming, and for this reason they have the same problems.

Usually they use the UMTS standard, which is the least performing of the 3G, and have a daily limit of a few Mb per day (best case scenario the device will have a limit of 100-500 MB per day).
If you go over this daily limit, the speed is drastically reduced making the hotspot practically unusable.

And to add, all of this is typically offered at fees double or triple the cost to our pices at WiTourist!