I have both mesh and leather. I really only break out the mesh when it's almost too hot to ride.
The mesh that I have is a Cortech HRX. It's actually leather on any area that would take a hit and heavy textile on the back. It also has CE Hard armor in it. I don't feel much less protected in it than I do in my leather, but the leather just fits soo much better.
John
NESBA #218
CBR 600 F4i
Built it Frame-up.
Gear: Shoei X11 Bostrom Rep, Teknic Chicane Jacket, Teknic Violator Gloves, Sidi Vertebra Race Boots, Teknic Speedstar Suit
Mods: Scorpion Carbon High Mount, PCIII, Supersport Undertail, CA Integrated LED Taillight, Targa Cowl, LP Short Stalks, Pyramid Hugger, Shogun Frame and Bar sliders, Corbin Saddle.