Skaliwag, I never have tried the MG65s [they seem kind of new to me]. I noticed they are heavier and more expensive.
The Karbonite servos have really performed well. I stripped gears once while flying .15 powered 3D with a huge rudder and lots of throw doing spins, then reversing the rudder full opposite. Basically being stupid and destructive. The servo hung in there for a few flights and now I have an idea about what is too much for them. I use them in all the racers, but they use very little control throw. Vibration would be their biggest enemy but so far so good.