As your experience already shows, consistency (i.e. skill) is not enough to beat the speed some of the current ESCs can deliver. Your GTB doesn't have variable timing I guess. There might be other factors, but if there was anyone with a variable timing ESC they can easily beat you with a lot less skill (especially on a favourable track). Technical tracks might take out some of the edge of new technology, but there's no guarantee.

Tekin is one of a number of variable timing escs on the market and their software and setup expertise is available to all users free of charge and in a very timely manner. This means that pretty much all the kinks are ironed out quite effectively.