Flying with a transponder in those MOA *is* a good idea,... and yes I'm especially thinking of Sevier MOA complex out towards Ely--pretty busy with F-16s out of Hill AFB, and with good radar coverage. But there are no guarantees anything will save your life. Communicating with the appropriate ATC facility can also help. You can always contact them, find out if there is something happening, decide to stay on frequency or tell them you need to leave the frequency. Newer radios with the ability to guard a second frequency are handy.