I'm late to the discussion (again).
Before going to Mexico last year we were warned of dire consequences if we didn't get a hard bottom dinghy. Since we already had our Zodiac 10'6" high pressure floor dinghy purchased used in 2003, we figured we just give it a try on the Mexico trip. No problems whatsoever.
The dinghy rolls up for passages and fits into our roomy lazarette. It is relatively light too. It will plane with chunky me aboard using our 5 hp engine. Most of the time we have at least two people aboard, with planing not an option, we plug along with the throttle set a bit above "start". We could get by with a smaller engine.
We have added three very useful items:
On Defender's recommendation we got a Scoprega model "Bravo BST 12 HPP" electric inflator. It needs a better 12 volt supply than the typical cigarette lighter connection, but goes up to 11.2 psi for the HP floor. Having this handy encourages us to top off the high pressure floor and tubes periodically and makes inflating and deflating seem like not such a big deal. This summer the dinghy has been on the foredeck a lot and we have also towed it with engine off over shorter distances.
We like the Novalift for getting the engine off the dinghy. It is only a 2:1 tackle but it is not prone to twisting up the way the multi-part ones do. That means we need to use a winch for lifting (a tradeoff).
We found some Denard dinghy wheels in San Diego while on the way to Mexico. The pneumatic tires are big and the lock up/down system is simple, reliable and strong. They made it easy to beach the dinghy even on soft surfaces. We haven't tried beaches with sink-to-the-knees ooze!
Wet floor Tom? The other day I took the dinghy out solo after we had had rain during the night. The high pressure floor was dry but later I noticed my sneakers were wet. Hmmmm... Oh yeah. When the boat pitched up under power, the water hidden between the HP floor and the hull skin migrated to the stern and came above the floor. Oh duh, it rained the night before.