Hi there,
Cool subject… the typical Amazon unit has specs of
Parameters:
1.Work Voltage:DC 4.5V~5.0V (Seeed/Groves is 16Vdc)
2.Work Power:2W
3.Power Type:Female Micro USB Socket
4.Spray Diameter:5um
5.Spray hole:740 holes
6.Spray speed:50ml/h (108Khz) 20mm round
7.Work Temperature:0℃~85℃
8.Work Humidity:10%~90%RH
9.Driver Size:351915mm
Application:
1.USB humidifier
2.Perfume atomizer
3.Aromatherapy atomizer
4.Auto parts
5.High-end toys with large amount of humidifier
It has Lower output when compared to the seeed unit which I believe is better than the Amazon unit.
HTH
GL 
PJ 