Target Book cover- this is the image used for the audiobook cover too
I was only familiar with this story as a title of a First Doctor adventure and from a few still images of the titular aliens, never having read the Target novelisation that this is a reading of.
It starts off quite normally, that is, in the usual Who way. Alien planet, blustering Doctor and all that, before everyone gets split up and goes off on their own adventure.
Overall though I found this story a confusing beast. It seemed to want to be too many things. There are too many story elements injected into the plot. I suspect this is a result of the original television version having to be a certain number of episodes long and them having to fill that screen time with story. So we have a number of plots featuring the TARDIS crew, the humans they meet and goings on among the Sensorites themselves.
It also does something that annoys me in any fiction. The Sensorites constructs a clever analogy, like all good sci-fi does. But they then go ahead and ruin that analogy by having a character point out that ‘Hey! This is just like such-and-such back on Earth!’ Yes it is, we got that that already, thanks.
The book itself, written by Nigel Robinson, is well done, albeit with a few too many adverbs for my tastes. The character arc given to the Doctor’s granddaughter Susan is a strong one, and sets things up nicely for her future.
The audiobook is brilliantly narrated by William Russell, who of course played Ian in the original story, and he sounds like he is enjoying being back in the Whoiverse again.
All in all, I’d say this is a worthy addition to your collection. Maybe not a vital one like Earthshock, for example, but certainly worth a listen.