EZStreets and Superstreets are identical track, except the EZ is a bit darker plastic - (think of them as two slightly different colors of asphalt). I've mixed the two interchangeably.
As to height, in my answer above I thought you were asking about the height of the rails - the track itself. Yes, Fastrack, with its molded roadbed, is about 3/8 in higher overall than Superstreets in the sence that a loco on Fastrack would be higher off the carpet of benchwork than if running on the streets instead, but the rails on Superstreets/EX-streets are 'high' enough (flange groves in the road deep enough0 that most O gauge locos will fit fine.