We went for a run on the Carnival Spirit to compare it with P&O and Princess. Carnival had the pack and go packages we just couldn't resist, we booked for the lowest cabin but ended up on level 7, but most cabins are much the same.
The dEcor is a real eye opener, you were dazzled with the Egyptian theme of the ship, it was truly impressive. We boarded and departed the ship at Circular Quay which was great, no need to get to that white elephant location ( White Bay ).
Staff were pleasant and friendly ( as per most ships )and things flowed along nicely day to day.
Ship was originally meant to go to Mare - but we were advised a few days before departure of problems with fuel strikes so told Mystery Island was now to be used instead ( been to both, but preferred Mare as only been there once ). Noumea was to be our last stop, but apparently port was closed on us a day or so before we were to arrive, so ship went back to Isle of Pines again ( were there two days previous ), but this was not Carnivals fault and these things sometimes happen on cruises. ( Last cruise we missed two ports around Australia ).
Food was great with one small fault - this being the Dinner at the Bistro - Only one hot food section open - don't expect any vegetables. But you can have salads or pizza's or toasted sandwiches, just don't expect vegetables. Also it is a bit like P&O for desserts in Bistro - cakes and bits of fruit unlike Princess which has everything ( ice cream, pablovas, cheesecakes, apple pie etc ).
Entertainment was great, live shows with the band were fantastic and they had different shows then the ones you see on Princess and P&O. Late night Comedy shows were good and usual Trivia but with extra Trivia on top.
However, they lacked a bit or other entertainment events you see on P&O and Princess - like no Quilling, Scrapbooking, Plate Painting etc that some people like to do, also not things like Charades, Celebrity Heads, etc.
No big screen on top deck as per P&O and Princess, but it has the waterworks for kids and big kids, putt putt golf and a basketball court.
The ship is bigger than P&O or Princess lines.
Beer prices are more than others ( I drink lights and are $5 on others but $7.50 on Spirit ).
Average age of people was probably 40 and I guess P&O were about 50 and Princess were about 60y.
So overall I would say it's a great ship for family members of all ages, would travel again if it went somewhere interesting north, probably looses a lot of attraction if it goes away from warm weather.