A lot of tennis shoes sell comfort as a cloud. Then you play two hours and the cloud is gone. The insole is packed. The sock is wet. Your heel is sliding.
Comfort that only works in the shop is not comfort.
What we mean by it
The insole stays comfortable when you're sweating through a long match. The upper doesn't chew the little toe. The cushioning still pops when you're grinding on the baseline.
No blisters. No hot spots. No managing the shoe.
The third set is the test
Anyone can feel good for twenty minutes. The question is set three, wet socks, hard court, late cut. If the shoe still holds, it did its job.
That's the only revolution we care about.