We had wanted to go on IOS for a long time and although wasn't disappointed, wasn't for us. Several reasons really, far too big, twice the size of others we have been on and this was our 10th.
Firstly when we arrived on the ship, we couldn't find our cabin, it didn't matter who we asked and was sent in one direction, once arriving there, was told it was another so initially very frustrating. Eventually after three quarters of an hour, one of the staff requested someone to take us to Cabin 3309. Unfortunately the chap who was taking us couldn't find it either. However, eventually after a couple of days we were able to find the cabin ok - as long as you knew which end you were!!!
Secondly, due to excessive noise above our cabin (3309 Deck 3), on the third night with very little sleep, I rang Guest Services and in turn Security came to see us. At first the lady couldn't hear anything, blaming it on the "rocking of the ship" and then heard what we did.
Excellent and Maria (housekeeping) first class. Nothing too much trouble and always with a smile!!