I have used Sutro for a couple of seasons and have seen them go from startup to full production. Sure some hiccups along the way, but no other company has a product that uses liquid tests and I have found that their wireless connectivity is great. I have a large back yard and my hub is inside the house but still stays connected to the monitor in the pool. Wifi isn't an issue anymore like it was with pHin and Water Guru.
They had customer support issues with the demand from this past season I was told, but they always compensated if service was unavailability or I got a bad cartridge and they said they added additional staff.
Using Sutro has saved me a ton of money since I can now run my chlorine at 2ppm and can keep an eye on it daily and if it starts to drop I can adjust before my pool goes green. I also don't have to worry about my pH ruining my heater and I can keep it dialed in with the daily tests.
Overall I'd highly recommend and if you have issues that aren't resolved then ask to have a customer support manager help. I did that and the issue was resolved within a day..
