We've done a
DCL Baltic cruise, a Merry Time 4 day to Cozumel, a Med cruise on MSC, French Polynesia on Oceania, and a river cruise.
I like DCL. It's no where near the same category of crowding as WDW. I WANT to like WDW, but the last few trips have been a challenge due to crowds, and we've been going for decades. We honeymooned there 27 years ago even.
I like to sit by the pool, and DCL's singular pool is a con, in my mind. It's crowded. Kid soup. The adult area seems to be irregularly policed as far as kids having access, from what I've read here. I'll admit I didn't use it much.
That said, the Med is port intensive. If you want to see the Med, for me, paying for DCL prices is not the way to go. We had an amazing time on MSC, as we went concierge (for less than half of what the comparable non-concierge DCL cost would have been, saving enough money to do a week in France prior to the cruise, arranged by an agency so no extra work for me.) Was it DCL? Not even close. Was it an amazing vacation? Absolutely. The concierge area was fabulous, the service very good, and our "bonus" France trip was fantastic.
Our river cruise was fun, but they can trend VERY sedate. I would think carefully about what you like to do in the evening and how long the ship will be in port vs sailing. U by Uniworld caters to a younger crowd. The average Viking age skews much, much older, and I'm pretty sure they don't even allow kids to sail. So no kids, but maybe not a lot to do at night either.
As for excursions, after dipping our toes in the DIY excursion water (we did 2 DCL and 2 I organized on my own for our Baltic cruise) I've never done a ship tour again, on any ocean line. TripAdvisor and CruiseCritic can help you find pretty much anything to do in any port. It will be more personalized, a better use of your port time, and frequently significantly cheaper. River cruises are a different beast due to docking location and time changes that happen continually.
