Shutting off the receiver is ideal. Think of this unit as a small computer. Every once in a while it is best to turn it off and back on again. It will perform better in the long run. I know stiletto 2's will have huge problems if they aren't shut off every once in a while.
I've left mine on for weeks. But it is a good idea to turn it off every once in a while. Take out the battery for a few minutes and then turn it back on