Having been on a med cruise, and taken excursions, as well as DIY, but not ABD, here's my IMHO:
getting off the boat early (I saw the clock on the video as 7:01) for all ports would be too taxing for me and certainly my teens. If you're an early riser, not an issue. But being on a bus at 7 likely means meeting at 6:45 or 6:30 and eating by 6.
From the video, you do get to see A LOT (vatican AND colosseum). However, we much prefer mixing long and short days. $5K for 5 ports for 2 is $500 PP/port. The guides look great. But, is it worth the extra $ for getting off the boat 1st, (let's assume) a more engaging guide and the same group of people for each port. On other shore excursions, all of the details are typically taken care of for you, as well, but the guides might be from vendors. I have been on 5 European cruises, both DCL and others and I don't ever recall a "bad" guide and many were excellent. They might be more matter of fact historical knowledge, but all were fine, IMHO.
Also, in hot summer, my family wanted to do a shorter day and get back to the boat and enjoy.