I have only used it 3 times, so I can't yet speak to it's efficacy, but I've already developed several concerns. On the 3rd use the sticky is already gone and it doesn't hold long enough for me to get the armband on- it keeps falling off. I'm increasingly concerned with the location requirement. They claim it's necessary so they can get date and time and diary feed info. Basically this means if I'm outside of cell range and don't have access to wifi (which is fairly common, especially when the power is out since I live in a cellular dead zone), that nerivio is denying me treatment. There should be a way to use the device then upload the info when a cell signal is once again available. I find this location requirement to be incredibly creepy and very 1984 Orwellian. I have told nerivio my concerns around this and I'm waiting for a response. Adjusting the intensity can be very time consuming. After a few minutes into treatment, the app "disconnects" from the device, tho the device is still delivering treatment. What this means is I have to open the app, give it permission to access my location yet AGAIN, it logs onto the device, and only then can I adjust the intensity. This could be avoided if they let you increase or decrease intensity directly on the device itself. This also wouldn't be such an issue if the intensity didn't feel like it changed so much on its own throughout treatment. Without me changing it, the intensity varies between barely feeling it at all and full discomfort. Because of the amount of time it takes to get the app to log back into the device so I can adjust it, it will likely soon drive me to just removing the device mid treatment. I have asked the bot several questions, which it has been unable to answer. On the plus side, it looks like a real human being monitors these, so concerns eventually (hopefully) get addressed. If I am able to edit my review, I will update it after I see how my concerns are dealt with.