Amalfi coast pre-cruise

It depends on what kind of experience you are looking for--one is a resort town, the other a large city.
What time will you have to depart to ensure you are on the cruise? That might help make the decision.

The departure time will depend on whether we're staying in Naples or Sorrento. We'd like to get to the cruise port by 2:00 PM.

Have you cruised from Rome before? I'm not trying to upset you, but it's a distant, annoying cruise port. Does your ship board at 2PM?

Priano is very "distant" from both Sorrento and Naples. Are you familiar with the Circumvesuviana train? Would you consider departing Priano via Salerno?

Sorrento and Naples are not comparable. The first is a postwar cliffside, purpose- built resort with no real beach. Naples is steeped in art and history and diplomacy, but grimy and under-funded.

Can you tell us more about your travel style and fill in your home-city in your Profile, please?

The "safest" answer is Naples. Frecciarossa trains are much cheaper 2.5 months in advance but non-changeable, non-refundable.

https://community.ricksteves.com/travel-forum/trip-reports/surviving-naples

https://community.ricksteves.com/travel-forum/italy/amalfi-coast-for-5-days-where-to-set-base-from

I know you'll have to leave Sorrento earlier, but the day before, will you have time to see/do anything? I would think about if you want to continue the relaxed vibe you have in Praiano, or if you want to jazz things up a bit.
I totally get why one might prefer Sorrento over Naples, but it does not mean there is anything wrong with Naples--it is an ancient city with a lot to see, and yes, it can feel a bit chaotic. So, think about how you'd like to spend the preceding day and the morning before you leave.
Another place that would be calmer but put you on the train line is Salerno.

We are thinking about going to Pompeii the day before we leave for the cruise. I realize Naples is closer to Pompeii than Sorrento.

It's pretty much a wash between Naples and Sorrento as far as Pompeii is concerned. Naples may be about 10 minutes closer, but the time spent getting to the train station for the commuter train is greater, while passengers merely get on the train in Sorrento and travel to Pompei Scavi. The time difference is negligible.

For an experience, Naples is superior, while Sorrento is a laid back resort area. I'd pick Naples over Sorrento for last night stays, given the logistics of getting to the cruise port. Figure 2+ hours Sorrento to Naples (I've added in time to ensure that you get to Naples when a train is actually leaving). The trip to Civitavecchia is between 2 1/2 hrs and 5 hrs, depending on train.

Leaving from Sorrento will increase your stress level on a day of departure.

Because Pompeii without (or with) luggage is a Metro-kind of trip, the distance by commuter train is of no importance.

Google Maps is your friend.

Here's how it might look in either case, but aside from logistics, we need to know what kind of place you'd prefer to be in.

Check out Praiano, go to Sorrento (private driver would be my choice here)
Circumvesuviana to Pompeii and back
Stroll in Sorrento, get up in am to depart
OR
Praiano to Pompeii via private driver, store luggage
Pompeii to Naples
You might even have time to see the stuff from Pompeii at the archaeology museum depending on how early you start and your stamina
stroll Naples, get up in am to depart
That's a long day, but you'll have the cruise departure day to recover.

Consider Salerno. Not much longer by train to Rome than Naples and it has an interesting historic center and a large sandy beach and pretty seaside promenade.

https://community.ricksteves.com/travel-forum/russia/termini-station-to-civitavecchia-cruise-ship

Thanks everyone for your input. Really appreciate you all taking the time to provide your thoughts.

Any suggestions as to where to stay in Naples?