The reviews are partly excellent, and Final Fantasy XVI seems to be selling well. Yesterday, Square Enix announced that the game has been shipped (physically) and sold (digitally) in a total of three million copies.
The wording is a bit tricky because in the headline of the press release, they mention three million players journeying to Valisthea, while the actual text indicates that they (as usual) count the number of physical copies sent to stores, rather than the number actually sold.
As mentioned, the game is loved by many, although some believe that the gameplay has strayed too far from the turn-based and group-based battles that characterized earlier installments in the series.