I just switched my Go to Neverstop for the next month, as I'll be at my parents' for multiple weekends. If you want a review of the service/experience, skip the next two paragraphs...
At my parents', a couple miles outside a town of 10,000 that can get 300M TWC, it's your choice of wireless provider for internet...and none of them are particularly good. Their choice is (and has been for awhile) residential LTE at 4M down, 1M up for $50/mo, unlimited, from a local provider. Said local provider hands out 4G wireless routers with 10/100 Ethernet, 802.11n and an LTE modem that supports band 12...with a couple 5db antennas that take RSSI down to the high -50s, so we're talking about something that's marketed as home broadband here. That company has 5x5 of Band 17 that all their residential customers use; mobile customers on the same provider are limited to HSPA+ last I heard in order to keep the LTE clear for fixed use.
All that to say that my hotspot likely has more capacity that it's pulling from than my parents' residential connection...particularly since there's a B41 cell site downtown (I can't reach it out here, but that takes the load off B25/B26).
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I've had Karma for on the order of two years, and the Go for on the order of four months, so I know the drill as far as getting connected etc. goes: connect to the network, log in if your MAC isn't remembered on the device, see the splash page showing how much data you have left (I have just over 20GB...I've gotten, and used, 5GB from referrals and 1GB came with the device). In this case, I logged in and then looked for an option to switch to Neverstop...and was told to do it from the app.
So I opened the app on my 5X, updated my billing info (the card I used to buy my 20GB of data expired a bit ago), and told it to switch my account to Neverstop. I was asked to confirm the $50 charge, then emailed a payment confirmation. The final screen on my phone for the process said that the month of service would start the next time I logged into my hotspot.
So I connected, logged in (pretty sure I was asked to log in even though that particular decide was authed to the network before)...and presented with a screen telling me I was almost ready to use Neverstop. Turns out, the device needs a firmware update (automated reboot required) to get Neverstop going. I let the update load...the ETA was 5-10 minutes and the actual time was within that range. The service helpfully told me I'd get an email when the device was ready to go, and I got an email at the end of the process as promised.
At that point, I was forced to log in again (I'm guessing the reflash cleared the MAC table, partially to avoid multiple devices immediately exceeding the three simultaneous device limit)...and was good to go from there on out. The splash screen said I had Neverstop at 5 Mbps;sounds like they'll have higher speed tiers or higher simultaneous device counts as extra-charge options in the future. Speeds on speedtest.net were within a few hundred kbps of 5 Mbps in both directions (yes, 5 Mbps symmetric unlimited LTE for $50/mo!), with uploads being closer to 5M than downloads. Not bad at all considering that's about what I can get on my 5X...or the Go when I'm paying per GB...at this location.
I have yet to test how simultaneous connections to the hotspot from different client devices fare; I'd expect the 5 Mbps to be shared between devices, but who knows...maybe the service would allow 15M down spread across three devices if the network can handle it. Will post back here when I test that (shortly!).