carbohydrates are essential for optimal metabolic function, particularly with respect to liver glycogenation and the cascade of metabolic effects related.
with low carb the energy levels that you experience may not be as good (better energy levels typically = better workouts, longer cardio, etc)
with low carb you may not expereince the same thermic effects- because of low liver glycogen effects.
thermorexin still works with low carb, it will still increase metabolism and fatty acid utilization.
IMHO its much better to manipulate carbohydrate metabolism and use quality carbohydrates than to go low carb.