I'm with Octopus. They make good use of smart meters - for example, I'm on a tariff that gives me 4 hours of super-cheap electric overnight (which I'm using in these low-light winter months for EV charging and will save a worthwhile amount over the coming months). But that's the simplest of...
Get rid as soon as you can. Their back end billing system is flaky, and their customer support when it goes wrong is really, really poor. I was with them for energy and broadband last year, until they "lost" a broadband payment they'd taken through direct debit and starting chasing me for debt...