There is a big difference. The GTB is a sensored brushless esc. The tekin R1 is a sensorless. Between those 2 go with the gtb beacause its a sensored esc. With my personal trying of sensored vs. sensorless, sensored performs alot better the sensorless.
Losi 8ight-T 2.0 Race Roller/Losi 350/JR 9100 Servos/Spektrum DX3R
BMI Copperhead 12/Thunder Power Lipo/Futaba Servo/Express 17.5/Spektrum DX3R