Whilst the character has not featured subsequently to the second series finale, he went on to appear in a Torchwood Magazine comic strip and Marsters has stated his interest in reprising the role on more than one occasion.

John leaves Earth disgraced after his initial self-interested plot is foiled by Harkness' Torchwood team, though returns in the series finale "Exit Wounds" where he is eventually given a chance to redeem himself.

John Hart is seen to have observed Ianto's funeral from a distance before later settling in Mexico, earning a living by buying and selling alien artefacts washed up from a rift similar to the one in Cardiff.

[7] Marsters accepted the role on the basis of a "really good script" and "a really fun character" stating that as an actor he is attracted to "playing people who are evil, don't care, and have no guilt.

"[8] In an interview published to the BBC Online news website in July 2007, Marsters indicated that he was "really" excited about his character, who he revealed would be "naughty" and "a bit of a psychopath.

[8] Chibnall, Marsters and producer Richard Stokes discuss the role of "Exit Wounds" in developing John's character and placing him on a redemptive path.

[12] Stephen James Walker, a writer of reference works on Doctor Who and its spin-offs, notes that because of the reluctance of Hart's collaboration with Gray and his remorse for his actions the episode leaves the audience "a little more favourably disposed" towards the character.

"[15] Whilst The Daily Mirror's Jane Simon expected that the physical contact between Marsters and Barrowman would result in "somebody's sci-fi fantasy" being realised she saw it dashing her "hopes series two might serve less sex, less rubbish aliens and more credible drama".

[18] Ben Rawson-Jones of Digital Spy felt Hart's arrival to be "self-consciously iconic" in providing "swagger, innuendo and a wonderful Star Wars reference".

He felt that overall the characterisation verged "dangerously close to parody at times" but this didn't detract from Marsters being "a joy to watch, in a similar vein to his role in Buffy.

"[19] Charlie Jane Anders commented in regards to the episode that ""Spike" is pretty great in his Adam Ant jacket, with his paralyzing lip gloss and his zany sexual innuendo".

In June 2010—following the announcement of a fourth series to be produced as an American co-production—Dan Martin felt that James Marsters would be the "obvious first box to tick" in regards to new cast members for the programme.

[26] In March 2012, John Hart made SFX magazine's reader voted list of the 100 sexiest male characters in the history of film and television science fiction and fantasy.