Re: Keep it at a dock or on the hard?
I guess the biggest downfall would be if you ever like to be on the boat at the marina while in the water. Our boat is on a mooring from May-October, and we spend many nights and a lot of time on the boat at the mooring.
I don't think the launch is that big of a deal, assuming you have a good ramp and adjacent dock. Once you get it down, you can probably get it dropped in within minutes.
A pro would be that it's probably better for the boat to be stored dry in the long run, and you can more easily work on the boat all season long as needed.
For me, I couldn't give up our mooring for anything, as we really do enjoy our time there when not out sailing or visiting other locations.