It sounds like the inflatables are more work, so it seems like the inflatable would be more likely to injure your shoulder for the actual paddling than the hard side kayak. If you are caching in a group, you most likely would be able to get someone to get you loaded and unloaded if you wanted to do the kayaking bad enough.
We ended up putting our kayaking on hold this summer until my surgery healed. I'm hoping we are back in our kayak this fall. Getting the kayak loaded on the roof is challenging after you've been paddling for many hours. I think one of the most recent times we went kayaking with the group, Houston Control was nice enough to help Stan get our kayak loaded onto the roof.