The last two years we have travelled with my folks and his folks and my sister. 2007 was a Panama Canal transit cruise (amazing!!) and last year was a Sea of Cortez cruise (also a wonderful trip).
We've figured out that, at least for now, cruising makes sense for us all as it gives us the opporunity to travel together, but do our own things. We also really love getting together for a nice long dinner... and the associated pampering by the wonderful staff.
One of our difficulties is that my mom is in a wheelchair. She's a great sport, but some things are just not possible. Tender ports (where you have to take the little boat to the pier) - not possible for her. And she requires special accomodations. Like enough room to get around the bed to get to the door or the bathroom. Roll-in shower. That type of thing.
You would be astonished at how hard it is to explain that to folks who are trying to sell you accessible rooms on a ship (or anywhere for that matter). The requirement that there be no steps to get into the shower actually means that THERE CAN'T BE ANY STEPS. One small step is still a step.
Hawaii is our next destination (probably). I'll be on the phone with the cruise line. For many hours. The good thing about all of that is that next winter/spring we will be on a boat to Hawaii!