The hypervolt system looks a lot nicer than a Zappi but isn’t the best on the software side if I am honest.
I own one, I’ve not had any problems but I know a lot of owners do be that WiFi connectivity, crashes, scheduling randomly not working or inaccurate energy usage data. I’m sure some of the issues are user error or unrealistic WiFi expectations but some certainly are not.
You also have to manually switch between solar mode and schedule which is nuts, lots of people have forgotten and awoken to an empty car. They promised they would fix that months ago but it keeps getting pushed down the to do list.
Like I said, I’ve not had any problems (I don’t have solar yet either) but you don’t have to look far on Facebook owners groups to find a lot of complaints about the software. I’ve also noticed a few complaints about grey plastic plug holster fading and white plastic units yellowing from UV. They don’t consider it to be a warranty issue.
I don’t own a Zappi but I hear far less complaints about them, you can just tell an engineer designed the outside and didn’t ask a more aesthetically minded person if it was ok for the front of the house first.