RIB
I think it really depends on where and how you cruise. We used a light, cheap soft-bottom inflatable for years and moved up to a RIB in 1993. With an 8 hp outboard it is a fast, multipurpose, boat that we use as much more than a dinghy. We can anchor miles from our destination and have a reliable, secure, dry, transport back and forth. Some weekends we use it for fishing and touring the local creeks, and leave the big boat at the dock. It is 125 lbs empty, without motor. It can be hoisted onto the foredeck with a spinnaker halyard, but on out H-34 it leaves little room to handle the anchor, so we mostly tow it. I think that towing it offers many advantages here in the Chesapeake. Though it takes a half knot off the cruising speed, it is ready to immediately run out an anchor for kedging off the shoals. It has yet to get into trouble under storm conditions - the extra weight of the glass bottom keeps it from flipping. Rowing it is cruel punishment. On a larger boat like yours, many people inflate their dinghys and keep them covered and on deck all summer. I see no down side to a RIB if that is how you are going to use it. For voyaging, the high pressure inflatable that can be stowed out of the way has a big advantage, but I have trouble thinking that it will take beaching as well as a RIB. Those coral beaches and stone ledges are tough on hypalon.