I love GHL hardware, but absolutely hate their software. I still have my GHL Doser 2, but it's in a box as I now have Sentia Dosers running both tanks. Their app is pretty good and I don't need to connect it to any controller. I have an apex on my main system, but I never liked the DOS, as I thought is was way too big and overpriced for two dosers. I aslo hate Ecotech software, so the Versa wasn't even on my radar.