Astounded by Sound has an excellent collection of reviews and rankings of all of Bowie, including some spot-on thoughts about Blackstar:

There are no other remaining and widely popular musicians of Bowie’s sadly rapidly depleting generation who would be capable of making a parting gesture as potent and startling as Blackstar, it’s that simple. The songs on Blackstar that deal with mortality and impending death form an artistic statement that has few parallels in popular culture, let alone music. For a while at least it is inevitable that the “non-death” songs will be overlooked, but they are an important part of what I’ve little doubt will be seen to be in years to come as one of Bowie’s best albums.

I can’t get over how experimental and totally prog Bowie’s last release is! It’s awesome. Chorus angelorum te suscipiat, et cum Lazaro quondam paupere æternam habeas requiem!