Charging network is another big thing I need to consider, but with Ionity expanding across the UK, and InstaVolt coming to McDonalds soon will it be that big of a difference?
It will remain a massive difference. Note how many actual chargers there are at the average Supercharger. Note the number of charge points at the average (and planned) rapid charger locations. Then note the frequency of non-functioning equipment at non-Tesla chargers. And then there's the competition from many different makes of EV wanting to charge at those chargers. Weigh this up carefully ... before making the decision ... to buy a Tesla.