Ok so driving from VA to Moab is a haul it takes a full 3 days. Driving time alone you are looking at 6 days. Since you have so much driving I would make the drive part of the adventure. Definitely plan to do things along the way not just slugging it to get to Moab. One problem though is Colorado is right along the way and a must see, but May is too early to wheel the high country. Also full disclosure I have not been to a cruise Moab but I have been going to Moab for 26 years starting when I was mountain biking as a 13 year old. Moab is a great place if you like adventure; mountain biking, hiking, rock climbing, jet boats, 4 wheeling, motorcycles, atv's, unimog tours, you name it. It might be nice to go to an organized event your first time out there, but seeing as you never know when you will be back it might be nice to go later in the year and do Colorado, etc.
Was kicking around going with the wife a few weeks ago, time off work is hard to come by in my business. Who has been before? Worth spending all my vacation days driving there/back/enjoying the event?