If they build supercharger locations here in Europe (as they should (or minimally include CHAdeMO), or I will rethink my reservation), I want each location to have two 90 kW DC superchargers, and at least two 30 kW AC three phase charging points. Superchargers will be out of commission from time to time, as there are electronics involved, but 30 kW AC is just a dumb connection to the nearest tranformer, so it should be very reliable. This means that pretty much the worst case if you pull up to a charging location and one supercharger isn't working, and the other supercharger is occupied with two additional cars waiting to be charged, you'll be at the location for 2 hours instead of 45 minutes. That, I can survive.
Having to charge on a 230V 40A point for 7 hours would be unacceptable, though.