I have only worked with two brands of SWG's, Pentair and Goldline. I have had a lot of the Pentair units stop reading salt levels correctly not long after installation (1-3 months). If they survive this period, they seem to work excellent. Goldline aquarite cells have been very reliable for me though. Early models (before mid-2006) were very poor and failed frequently, but since then, I have only had one in over 100 fail to date. That is, that wasn't due to abuse or poor maintenance.