Flat or contoured?

There is no "better" with different shapes, except what's better for your specific body.
Just a millimetre or two different in your diameter to the ring will make as much difference, and one problem with non-flat rings, is the "diameter" is only an approximation.

Even then, it might be that in the heat of summer a completely different ring may be better than the one that's best for security and comfort in winter.

It really is a case of try what you think best, but be prepared to try alternatives, even if they seem improbable.

What can work well if you're still experimenting with finding the best fit, is to get cages and rings with the same compatible locking mechanism, so you can mix and match both rings and cages to see what suits you best.

 

Completely agree with @bondinchas on this. I’ve had both styles, and while the contoured seemed like a great idea, for ME, the flat ring is better because it creates a consistent gap between cage and base ring.

You might just need to experiment.

 

The curved rings always create too much of a gap for me. My testicles are smaller than grapes though so may not be a problem for you.

 

I seem to be having the same problem. Thick strotum skin and small testicles.

 

But I prefer the shaped curved base ring