We booked reservations on the Bliss for the Mexican Riviera last October and again to the Caribbean January 19th. The ship has greatly improved with service levels and communications. The were less wait times for almost everything. Dan dan the cruise director and Mark the Hotel manager were outstanding making this a really good cruise. The only down fall for us was the excursions and that wasn't reflective of the cruise itself. The food was really good everywhere we ate. The staff was very friendly and attentive. There were times that parents were not watching their kids and they would push all the buttons on the elevators and run up and down the halls but that is just lack of good parenting which is visible and irritating to other passengers. The spa was fairly busy all the time and I wish they would limit the number of passes they sell. The biggest improvement from the previous Bliss cruise and this one is that they implemented a new policy that if you put items on chairs to hold them and you do not use the chair within 30 minutes they will remove your items and hold them at the desk for you to pick them up... Huge benefit because now it was much easier to enjoy the sun deck!
My advise on booking is that the difference between the balcony and the mini suite is not worth the cost difference. NCL used to provide slightly better amenities for Spa Suites and Mini Suites but now since they don't it's hard to tell the difference. Other than a double sink we didn't see any difference.