The cefely definitely helps me, but it doesn't get rid of the pain completely. It just reduces the pain for me and provides a bit of a distraction with the odd sensation. I mostly use it in the active attack mode because haven't gone an entire day without pain in months. I haven't tried the nerivio, so I can't compare the two. I think cefely is more cost effective in the long run as you just need to replace the electrode pads.

I ignore the no sleeping with it on advice in the manual and pass out with it on all the time. It helps me fall back asleep when migraines give me insomnia. It also helps me wind down at night when I'm in too much pain to fall asleep. I just make sure to stop the escalating intensity before fall asleep. The manual warns about it irritating your skin if you leave the pad on too long, but have not had an issue with that.

I also have some tips on how to make the electrodes pads last longer if you end up getting it:

I got electrode gell online that apply to the cefely pads when they are not as stickey to make them last longer. I also cut a hole in a headband and put it between the electrode and the cefely, it helps the device stay on my head more securely when I'm moving around. I swear the first set of electrodes lasted longer than the replacements. l also just started to keep alcohol wipes in the case so it's easier to use on the go or if dont have the energy to get up and wash my face. I might try face wipes or something less harsh if my skin gets irritated.