What we should be concerned with when reading reviews and considering a purchase is the capacity size of the disc, whether Blu Ray or 4K. My understanding is that they come in BD~100, BD~50 and BD~25 and the actual encode level [the higher the better] which can be a determinant in the actual quality of the picture and sound! Blu~ray.com always lists the disc capacity size and encoded levels in their reviews. For instance, some 'cheapy' releasing companies try to fit a 2 hour movie with DTS~HD MA 5.1 on a BD~25 disc and encode it at a lower bit rate resulting in subpar transfers. Mill Creek Entertainment is famous for this anomaly which is why their pic/sound reviews are LOW.
And when they try to squeeze two movies on one BD~25 disc ... BEWARE! They should've used a BD~50, at a minimum, to accomplish the task!
Since the new encode of TWILIGHT is on a BD~50 disc and features only monaural sound and runs 101 minutes .... I'm sure Arbelos, the releasing company, has eliminated the color banding issues you encountered on the previous BD disc....or the review would have called attention to this deficiency in their review.