I bought one in 2012 and the solenoid has stopped working. (This is the second time) I usually take it apart and clean it our and grease up the components, but I'm tired of having to do so.
 It has also developed rust on the magnetic joint (it's swollen with rust). The LED ring on the base stopped working after the first year. The placement of the battery pack needs to be strategic as it affects the touch.
Also don't get too much water on the base. Mine was properly installed, but the gasket wasn't tight so some water had dripped down to the solenoid causing rust on the metal pieces on it. I applied silicone after that and should have applied it at the time of install.
Warranty is done with, and despite it only lasting 6 years, I want to replace it with the same kind because of the touch feature (I don't want a motion sensing faucet).
I have an early version of the faucet (an open battery box design) and I sure hope the kinks have gotten worked out on this model.