I got a NuFace a while ago, used it faithfully for about 3 months, saw good results but got busy and forgot about it.
TBH the FlexEffect 3rd ed program and the new skin techniques taught in it are doing more than the NuFace ever did, so I probably won't ever use NuFace again.
Disclaimer: I don't sell, work for, or am in any way affiliated with FlexEffect.