I carry an 8' 9" inflatable dinghy on Weaver davits on my R-25. The R-25 has the same beam (8' 6") as the R-27. The bow of the dinghy hangs out three extra inches to port and the dinghy's stern is flush with the starboard side of the tug. I've not had any significant problems. My fenders are about six inches in diameter. I have occasionally rubbed the dinghy lightly on docks, pilings and lock walls, so extra care is required. When possible, I arrange for a starboard-side tie to minimize interference.
The dinghy has a slatted bottom and only weighs 58 lbs, so I can lift it using a single line attached to the port oarlock. I don't need a winch or block and tackle. As Jim Favors has pointed out on his boat, it does reduce rearward visibility. My wife prefers to lower it during cocktail hour to enhance the sunset experience.
My boat is documented and required to display the name and hailing port on the stern. Since the dinghy obscures this, I've painted the information on the bottom of the dinghy as well as the stern of the tug.
Any dinghy represents compromises, but the bottom line is that I'm satisfied with my current setup for my needs.
