The subject matter immediately is enough to grab the attention. It is a very sensitive and difficult topic to discuss, and if anybody has doubts about whether the execution would be tactful enough without being preachy, one-sided and too heavy that is understandable (those are common traps with this kind of topic and similar). Anybody though that has always admired how 'Law and Order' approached tough subjects and how it did so will be intrigued.
"Stiff" could have been too sleazy and exploitative. Or it could have been hard-hitting and moving. Luckily, it was on the most part the latter. The subject is not a novel one, 'Law and Order' did cases that involved comatose spouses quite a few times beforehand ("Coma", "Encore", "Grief", which all handled the subject even better than here), but "Stiff" generally handled it very well if not exceptionally or innovatively.
Maybe there is not an awful lot unique about it to begin with.
Once again, the denouement could have taken its time more to be explained, too much information explained in a hurry.
However, there is an awful lot to recommend about "Stiff". It is shot with the right amount of intimacy without being claustrophobic and that the editing has become increasingly tighter over-time has been great too. Nice use of locations too. The music doesn't get over-scored or overwrought, even in the more dramatic revelation moments. The direction doesn't try to do too much and is understated but never flat or unsure.
Script is intelligent, lean enough and thought-provoking, managing to not be too heavy-handed or one-sided which is very easy to do for a subject like this. The story is incredibly compelling and harrowing in the second half, the crime/scheme is one that makes one sick to the stomach even thinking about it and even watching it is riling-up worthy. The performances are excellent from leads and supporting.
In summary, very good though be warned that it is not an easy watch. 8/10.