Ahoy, Carol!
My husband and I decided to embark on our very first Back to Back cruises this past October on the super-fun Disney Magic. I was apprehensive, and had similar concerns to yours. Now, I am a B2B addict! I would love to do this EVERY time I cruise!
You are very smart to be thinking ahead. If you are booked in the same stateroom for both legs of your B2B, you do not need to pack up between cruises, which is awesome! The night prior to docking, instead of luggage tags, we received information about where to meet the Crew Members who would help us with the disembark and re-embark procedures. On our B2B cruises, we were in San Juan for the day, so we had plans to wander around and do some sightseeing while the Magic was docked.
If we had wanted, we could have re-boarded the ship almost immediately and enjoyed the time on a nearly empty Magic. I have also heard that you have access to your room, but we didn't need it.
The reimagined Magic has the raised beds like on the Disney Dream and the Disney Fantasy, which is a huge improvement! Now your luggage will slide right under for storage. Unlike the Fantasy, however, the inside staterooms on the Magic do not have magic portholes.
Also on the reimagined Magic is my favorite water slide, the
Twist 'n' Spout! It may look like a kid's slide, but we enjoyed riding it tremendously! If you are a daredevil, the
AquaDunk might be for you. It was something that I tried...once...and that was enough for me!
I hope this helps with your cruise planning! Please visit us here at the Disney Parks Moms Panel with more questions that will come "afloat" before your back to back cruises are here!
Happy Cruising, Tracy V.