GTB: It's an old speed control. Novak has the new kinetic coming out soon that is user upgradable.

Mamba Max Pro: Fast and upgradable but has a large footprint (May not fit in your car). Lowest cost of all the top ESCs.

Tekin RS : Low cost (second lowest in cost behind the mamba), user upgradable and one of the fastest ESCs you can buy.

LRP SXX stock spec: One of the fastest ESCs you can buy and very easy to program but ..... it's expensive and can't be upgraded. You will need to buy a new ESC to keep up with the latest and greatest software.

At the moment it looks like the Mamba, Tekin and SXX stock spec are around the same speed.