I just had a business trip to Spain, France, and Canada, and while I do have a work phone with an international plan, this was the perfect solution to having mobile data for when I was off the clock sightseeing, etc

If you are good about downloading Google Maps vis WiFi (whenever you have the chance) and otherwise carefully manage your data consumption, this can be a really good solution for maybe two weeks of steady travel around Europe

If you are only going to the UK this is a great solution because you can upgrade by visiting stores that sell Three network vouchers

If they could fix this problem it would be a super awesome solution