Rented the TEP wireless device for use in Scotland and Denmark for a three week trip from the U.S. from late March to early April of 2012. I needed this service for my consulting business at home in California. What I remember from this nightmare experience is listed below:
I did not have coverage in downtown Edinburgh in my third floor (ie, high up) hotel room. Had to use the hotel's wi fi. Had only intermittant service in Bilund, Denmark, where the room where I was working in on the second floor had a direct line of sight to the cell towers at the Bilund airport.
In a slightly more rural area of Denmark the service was horrible. (Everyone else's cell phone access was fine.) Most of the time I could not even get it to work. As a result, ended up not using it at all for the last week-plus of my trip.
My service was interrupted in the middle of doing some crucial work during the time they were probably doing their daily usage accounting (midnite)) and they did not reboot their service until about noon the next day.
More than a few days I was denied service the next day for prior usage overages, when I had watched and accounted for my usage on the device's meter, and KNEW that I had not run over.
They added charges to my credit card for overages, I did not have. They were not open for customer "service" at hours they said they would be.
They emphasized the need to return the device by mail within a few days of arriving home or you would be fined or even have to pay for the device. They took three weeks to send the mailing label which I had paid for ahead of time. I had to email and call them (in UK) multiple times to get them to send the label. They never did sign and return the "return receipt."
Everything you read about from others on this website is very probably true, based on how badly my experience went. This is, by far, the worst company I have ever dealt with. Do not do business with these guys!