I wouldn't presume to offer a review of this TV series, except that nobody else has done so and the series deserves at least one positive comment.
The earlier Hancock's Half Hour may be more recognizable to people who have never seen his work before. Sid James was a regular supporting character in those shows, and for a while other characters included Kenneth Williams and Hattie Jacques -- all three went on to greater fame in the Carry On films.
However, Hancock never liked the gags and funny voices that came with them, and this TV series marks the point where he left them behind (somewhat cruelly in the case of Sid James, I understand). Alas, a later step was to ditch the script-writers, Galton and Simpson, and it was all downhill from there.
Although IMDb pretends that there's no DVD, in fact The Very Best of Hancock DVD (region-2) contains five episodes from this series. There are some absolute crackers, where almost the only character is Hancock, or almost the only set is a single confined space, or both. The language of the episodes is also purer and more easily understood by a modern viewer (Galton and Simpson's wild excesses were put on hold for a time).
The Blood Donor is a famous episode, and also highly recommended are The Lift and The Radio Ham, which display the virtues of Hancock's comedy at their best. They all bear re-watching.
For people of my generation and nationality, Hancock is the master of comedy. It may be, however, that really he's a rare wine that doesn't travel well. If any of his work actually translates to younger audiences, this series will be it.