Schedule the Disney Cruise.
When our boys were younger we started cruising on Disney and they loved it. Now it is just the youngest at home and as an older teen, he still prefers Disney Cruises. Quite a bit of the cost for us is actually getting to the Port. Flights, hotel room, meals en route, etc. All in all the financial impact of the difference in cruise price is a bit less with all that factored in. This is what we have found for our family.
1. The people on Disney Cruises tend to be much nicer in general. Perhaps it is because everyone there is with family, or just the Disney vibe, or maybe because there is less booze and no gambling. Some little girl runs past, slips, and takes a header on a different line and people just stare at her. On a Disney cruise the tattooed biker in the chair next to her gets up to see if she is ok while 5 other people run over. We were definitely are more comfortable letting the boys roam on their own (or with friends they met onboard) on a Disney cruise.
2. The entertainment can always be counted on to be great. The little extras that your daughters will love is something they will remember for a long time.
3. In grand generalizations, the food is better, and dining is much more fun. Many other lines have great restaurants you can pay more for. Some lines and ships are hit and miss depending on age, size, etc. Disney has great variety (some lines have the same food with different names every night) and you can count on the quality being high. We have had great food on some lines, really crappy food on some, and average on some. We have never had bad or average food on a Disney cruise. Some have not been the absolute best, but they are always above average. Free soda, ice cream, and room service are also fun. For some reason kids love room service even if it is just a huge pile of fries.
4. We love the kicked back uncrowded fun on
Castaway Cay. Definitely rent the bikes and ride out to the lookout tower.
5. No casino and much less booze. No giant "Mall of the Sea" on an entire deck where people are constantly trying to sell you something. Generally no A-holes taking a cruise to get blasted and party.
6. Whether they actually are or not, Disney ships seem less crowded. You can always find a quiet spot to chill even if all 5 of you are together.
7. Verandas are nice, but we spend very little time on them. If money is an issue, get two inside rooms and take time to sit outside up on Deck 4. There is never anyone out there. It is very easy to spend very little time in your room. Basically just sleeping at night or napping in the day.
8. With very athletic teen boys I thought the lack of amenities (no zip line, no bumper cars, no flow rider, etc.) would end up being an issue at some point. It never was. If your kids want to go on water slides and zip lines for vacation, go to a park on land. Those are 10 times better. Compared to top end land based entertainment, the zip lines are tame, the water slides are tiny etc. The water slides on other lines that are twice as long as Disney are still tiny water slides - and they are all still fun.
9. If they are revived by the time you go, do the Fish Extenders. We have fun with that.
10. You will have fun with whatever you choose. We just find going on a Disney Cruise to be much much more relaxing for all of us.
I hope this helps. In our opinion, going at least once on a Disney Cruise it totally worth it. Some of the memories our boys talk about most are from stuff we did on Disney Cruises.