I have been on that same Elation cruise out of Mobile three times since I live only 45 minutes from the terminal and have been to Paradise Beach as well. Even though it is a small ship, my family and I really had the time of our lives on it last summer. It was great to be able to get around the ship so easily and not have to worry about getting lost, especially with my three children on board with us. The crew on this ship was fantastic and we enjoyed getting to know them.
If you want excitement combined with a beach experience check out the Passion Island by Twister boat excursion. The beach at Passion Island has all of the same amenities as Paradise beach, however, getting there (and back) is half of the fun. This really fast speedboat takes you on a 30-minute ride to the Island and takes numerous opportunities to do 360 degree spins in which the passengers get a good blast of refreshing sea water! It is a bit on the pricey side, but still less than $100 per person (I think it was $79 last time I went). Then you get to spend about three hours on the beautiful beach as well.
Just a suggestion.
Have a great cruise!