1) Transmission issues - I had to have my transmission replaced (under warranty with a fight) on my 2015 SR5 because of the torque converter shudder
3) Front differential groaning/grinding (TSB-0026-15) Replaced front left needle bearing
2) Rust - Seal your frame annually, wash off salt when you can. I live in an arid climate and still have issues
3) Slow - Already been mentioned