Recommended
I had a wonderful experience with Vision Global WiFi. I used their Verizon plan in the US (especially NYC area) and the signal was strong even inside buildings and most subway stations. Their support was great, the delivery quick and timely, the prepaid box to send the device back is easy to use and the postboxes where you can drop it are ubiquitous. It saved a lot of time in my trip, as there are public wifi but signup is not always immediate, while the pocket device is always ready and easy to operate. It also saved a lot of time to research the LTE bands supported by my phone and US carriers, which is a need: otherwise, your phone may connect to 3G or even only 2G, and that's so slow to ruin any trip. Overall, very performant and convenient, and their customer service excellent. Minor notes about the device I got: it's a bit bulky, but I guess they come locked from the carrier and cannot be replaced. It won't fit any pocket, you need big pockets or a small bag. The battery with the supplied charger takes a while to fully charge, and won't make a full day, so a power bank is advisable for anything but mild usage. I had mine, but they also provide one if requested.