This is a cyclical sort of answer, but the best is the cheapest policy that meets your needs.
Does you health insurance cover you outside of the US? Does it cover an air evacuation? Are there limites on the amounts it will cover for these items? If you have great health insurance, then this provision in the travel insurance is less important to you.
Are you driving to the port? If so, lost luggage is really not an issue for you as you will hand your bags directly to the porter who will load them onto the ship. On the other hand, if you are flying with a connection, coverage for lost luggage might be more important as your airline could lose your stuff. You don't want to be on a cruise with only the clothes on your back for 3 days till the first port of call.
Why are you buying the insurance? Are your personal finances such that losing the cost of the cruise is no big deal? If so, you are more interested in issues like trip interruption or cancellation maybe????
It is a real pain, but you really need to look at the fine print on the policies to make a decision. I was on the 7 day cruise that became 4 days due to Jeanne. In fairness,
DCL gave us a 40% refund on the cruise fare portion of our tickets...which is just about what it cost me to buy 2 extra nights at WDW at rack rate and to feed my family for those 2+ extra days. So, financially, it was basically a "break even" thing. Nothing will ever be able to give us back the 3 days we missed of our cruise, but we are alive and well and can cruise again. We met people on the ship who were getting (or thought they would get) $1000 per day for the lost days. Other people would get from their insurance exactly what they spent for those days. This was in addition to what DCL would give them.
So....only you can decide what is most important. Most insurances won't pay you more than your trip cost, no matter what unless it is under the medical clause.