I used a Hobbywing XERUN 150A sensored ESC with Tekin T8 1900kv in my XTM Rail and it was pretty smooth. Not as smooth as my RC8Be with a RX8/T8 2250kv setup but not too far away. It never cogged but it didn't start as smooth as it did with the Tekin ESC. It would kind of do a little lurch forward at the smallest throttle input but once on the way it was very smooth indeed. Power was very progressive. Was pretty surprised that a Chinese ESC could be that smooth.
Still if you want ultimate in smoothness then go with Tekin RX8/T8 combo but T8 motor with MMP should do a pretty good job too.