When it was first published I loved it and I still do after re-reading it recently.
The 'Hardness' of the SF does not obstruct the story for me, on the contrary. The avoidance of dumb stuff eliminates a "D'oh!" of disbelief when a less-educated author pulls a blooper. Makes for a smoother ride.
It's a well worked out (given the data available to the author at the time) realisation of a highly unusual world and its peoples - of varying and interesting character.
The mission and its kicker conclusion provides a thread linking this Gulliveresque exploration into high gravity regions.