[Ron in Maine]

To slip or not too slip... not even a question. Time on the water is what it comes down to in the end. With a slip, you pack your gear, take it down to the boat, start the motor (important lesson learned last year, start it before the next step), cast off the lines, and you are gone.
Coming back in, about as easy. No time to wait to launch or recover, getting on the trailer right, rigging for the ride home, then jockying around putting the boat back.
And if you suddenly find yourself with a little time, you just head down there and you are off. (Just remember to start the motor before you push away from the slip... if it did not start, say the batteries were dead or something like that... well, let's just say that you will be known by more than one or two people)