I honestly don't think there is a better supplier on the market.
I've been with them 2 years now I think it is but never had an major issue and any minor ones it's just an email which they sort out in a day or two
I certainly trust them more than I trusted any of the "big 6"
I had one issue when they installed my smart meter. It went from 0 to 999997 or something, a week before billing. Basically, it must have gone a step backwards but obviously has shown a lot forward. My bill was like £13k with the DD supposed to go out a week after that.
I emailed customer service, but also googled the founder (Hayden), found out their email structure and emailed him directly, in a nice way. They got out of them way to sort it.
Many years ago I had a similar severe issue with BG about a property we moved in and a meter that didn’t exist. They went out of their way to fine us, switch us off, put threatening notices through the letter box.
EDF was good in service but high estimates. I guess smart meters reign them in a bit.
Scottish Power was a good provider in the previous property, happy using them again. Bulb was just cheaper, we got £50 for being referred and £50 for referring someone straight after ;-)
I give anyone they move us to a chance, but not British Gas.