Whether the Allure (or Oasis) is worthy of a B2B cruise is subjective. Speaking for us, and that includes a 17 year-old son, one week was plenty. We were ready to leave. It was getting into sensory overload territory with us because of all the activities and noise from those activities. The first 3 or 4 days gave us the WOW thrills, but then the new wore off and we found ourselves spending more time in the cabin or the concierge lounge, just for some quiet.
We saw younger families that were constantly on the go and reveling in everything. They probably would love another week.
Our cruise had 6261 passengers (the max is 6360), and that included 1300 children and teens. The ship did an exceptional job managing so many people and the kids were never a problem. However, 1300 kids can make a lot of noise. No way I could take it for 14 days. Perhaps it would be different during another time of year when most schools are in session.