Though genuinely unsettling & respectfully chronicling the horrors of Dennis Nilsen's atrocities reliably, "Des" is somewhat limited by the fact that it feels as though it's desperately trying to be a David Fincher film - emulating his grim, distinctive signature style... Without actually possessing the benefit of having any of David Fincher's involvement in this project, whether it be his meticulous direction or the usual gratuitous production budget he tends to bring as a helpful added bonus.
That's not to say it's bad - far from it - but when the creators have so obviously tried to establish their own UK reimagining of Netflix's "Mindhunter", it's hard not to notice the shortcomings when you make that immediate comparison - though you have to commend a British broadcaster like ITV for even having the audacity to make an attempt - despite the fact that such a venture would never have been (& never will be) realistic or affordable.
However, there are positives & the obvious accomplishment is the show's faultless casting. For instance, David Tennant is a perfect choice as the title character & being the indomitable talent & national treasure that he so undoubtedly is, it's safe to say he continues to cement his legacy - after a career spanning decades - as one of the best working actors of this generation by delivering yet another astonishingly convincing performance as an utterly hateful monster. The way in which he embodies the ambivalent serial killer is both chilling & remarkable & it cannot be stated enough - he's incredible.
Hence, to conclude: is "Des" a masterpiece? No, but regardless, is it recommendable? Yes, absolutely.