Situation: Working by myself, recording myself, punching in.
I would set a punch region. Then set a loop region starting before and ending after the punch region.
With "loop continuously" unchecked, Sonar would play the section, stop automatically and cue up for another take at beginning of loop region.
Real nice when you are working by yourself and punching yourself in.
One key "r" is all you need, once for each take, no need to even press stop. Nice.