I changed my Electric and Gas to Octopus November 2018, then updated to Octopus Go tariff in January 2020, the whole transaction was seamless to date including the meter changes, I am still approximately £20 a month better off than my old supplier Southern Electric even with charging up my PHEV. For some reason we cannot get the Octopus Go faster rate in our area, just the Go rate, I am not brave enough to us the Agile rate
The Agile rate is for people who can shift pretty much all electricity usage around the electricity prices for those 1/2 hour slots, so people with powerwalls etc., plus perhaps people who live on their own like me who can simply please themselves when they eat, watch a television, etc. I’m looking at some power storage electrickery to use a lot of spare LiFePO4 cells I still have laying around unused (80 x 15aH, so enough to power the house between recharges for perhaps two days, plus I’ll put some solar panels up to help).