I had a really nice time on this cruise. My staff at dinner was excellent, but I didn't see my stateroom steward at all the entire trip. Nevertheless, (s)he did a nice job keeping my room in good shape. The staff at the casino was also excellent, however, I didn't find that random employees I came across on the ship were particularly friendly. Most of them would stare straight ahead and not say hello as I passed them in the corridors. This is unusual based on prior cruises.
The ship itself is aging, but still is a fun one. I enjoyed the water slides. One thing I would have liked was a pool in a more quiet area. The serenity deck (adults only) had two hot tubs, but no pool. The other pool area included extremely loud music, making it hard to relax and read. I didn't attend the comedy routines myself, but heard they were ridiculously funny. Food was good--certainly not excellent. Definitely eat in the dining room as much as you can. I found the food there to be far better than that served on the Lido deck.
I have previously sailed on the Glory, Liberty, and the Triumph (listed in order from favorite to least favorite). I found the Imagination to be relatively old and with a staff and food that left some to be desired. However, this cruise was still awesome and a good value for the price I paid. I remain a loyal Carnival customer.