I've not read Ian Marter's other novelisations but his version of the Reign of Terror was very interesting. It fleshes out the historical context of the story and makes a stab at explaining the often overlooked point of language by simply having the characters have to converse in both English and French - which actually causes some issues that were not explained in the TV version of the story.

The description of violence at certain points (Barbara's rejection of the jailer, Robespierre's capture) is more violent than would have been the case in a 60s show aimed primarily at children although is more accurate in the case of Robespierre. There's more general historical exposition (which I think makes the historical novelisations quite interesting) - often making use of Barbara's history teacher role. One of the points in this is that the fact that the characters are English and aren't fluent in French is a plot point - the Doctor doesn't have an issue blending in, Barbara and Susan can speak very well but stand out as English while Ian struggles to get by and this causes a number of issues (Ian speaking to Le Maitre in the jail, exposing Barbara and Susan in the Doctors office) which I think is interesting. This question was ignored mostly in the classic series and the TARDIS translation circuits are used as a justification in the modern series; so seeing this story use language as a plot point is actually really quite interesting.

Its a faithful retelling of the TV story in other areas and I broadly would recommend that over this - but I think both are interesting to look at.