Here is an absolutely fabulous simulator output that an engineer has developed in conjunction with his test equipment. It is by far the best simulator I have found, and is developed for ebikes but works for any permanent magnet motor system where the system constraints are known. everything is modeled, including thermal transfer over time. Find it at Ebikes.ca in the tools section if you want to play around with it.
What we are looking at is a 7 turn motor (motor A) vs a faster 5 turn motor (motor B). I have changed the constraints to have no battery or phase amp limiting to better reflect how RC car systems work, IE we are mostly constrained by system load, resistance, and inductance. As shown, the higher Kv motor produces more torque, more power, and more speed along the entire curve. Higher Kv will produce MORE torque at a certain voltage, until it reaches a saturated state, as long as the ESC is large enough to handle the current. If I "geared it down" too, it would absolutely smash the lower kv system in performance. The volt up gear down mantra I have pushed in the Ebike world as well, and it has been very well received and used.
This does not reflect the issues that higher Kv motors present to sensorless commutation, but gearing down gets around that. A 20% increase in Kv would ideally be met with a 20% increase in gear reduction so that the commutation rate was also 20% higher. Higher commutation rate gives better sensorless feedback and gets out of the "dead zone" faster all else equal.
Point being, with any sensorless system there will be a threshold of wheelspeed where low speed control becomes poor, but it is not because of torque loss. The fix is always more geardown or going sensored.