My Formula 4s got flat spots, sounding like a moped when I ride the bowl. I’m looking for larger sizes from 56mm upwards. I need mostly for very smooth surfaces and high speed, but sometimes also rougher concrete. I don’t have a need for ultra soft wheels.
A little late to the party but I can recommend the Powell Dragon wheels. I was looking for something that is rideable on rougher surfaces but let’s me do tricks on obstacles and in the park as well. If you ask me the hype is real about them and I’m totally satisfied. I saw that they also go up as big as 64mm according to the Powell website.