I have an Intellichlor IC40 and am in my 3rd season with it. I am not dis-satisfied enough to say that I wouldn't buy it again, but I would not say I am super-impressed. I have had the "flow-meter" go bad and had to replace ($40 part). No biggie, stuff doesn't last forever. One of the LED lights actually burned out (or more correctly stopped working). And now, 4th year in, I am having to replace the IECG cell. For the task of converting salt into usable chlorine, it seems to function as advertised, so I cannot complain too much.
My list of gripes:
(1) Number 1 is that I cannot "unplug" it to remove it for periodic cleaning. If I ever get around to it, I am going to cut the power cord and install a weather-proof plug socket so I can remove the device for cleaning away from the equipment. Seems like the manufacturer's design should already allow for this.
(2) Cold water shutdown. Because of science, the IC40 stops producing chlorine below a certain temperature (52F maybe?). I believe all SWG's are subject to this constraint. No big deal, except that the IC40 doesn't tell you that it isn't producing chlorine. So during the change in the seasons, I have to watch it closely or just shut it down early.
(3) Minimum flow. It requires a minimum flow of like 25 GPM or something like that to produce chlorine. Again, I think this has to do with the science of SWGs. My pump only measures RPMs and I haven't actually done a test to measure the flow, but it seems like I have to have the pump cranked up quite high for it to actually register a flow. I sure would like to have an SWG that I can leave running at a lower setting and let the pump run longer during the day at a lower speed. As it stands, I have to crank my variable speed pump up pretty high and run the IC40 at 100% output for a few hours per day.
(4) LED lights a little bit cryptic. I always need to refer to the manual when stuff starts blinking different colors, and some patterns are not listed in the manual; ugh. If I ever get spare time, I'll laminate that page from the manual and post it inside my pool electronics cabinet.
Agian, the device has been pretty reliable and it does what it is supposed to do: make chlorine from salt.