There is a guy (Artisan Electricians) who fits all models and does lots of Youtube videos of their fitting and features. I emailed him and asked his which was best expecting to get a 'wishy wahsy' answer and no . . he emailed back "Hypervolt is the best" and he gave various reason about reliability, software and backup.Are there any that should be avoided or that are wholly recommended? I realise its a bit of a minefield with earth rods, connected vs not connected, cost