A roomy campground, by a lake, in the mountains. Nice!
Lakefront spots are grand to back your camper onto, but they tend to go first of course.
The lake itself doesn't have a great swim vibe. I'd be looking for one of those pure streams closer to Arthurs Pass for a plunge.
Sandflies are far less rowdy here than other Arthurs Pass camping options (where they can be ravenous)!
The main negative is proximity to the road - that's where the lake side spots, further from the road with the sound of lapping of the water, are best.
Oh yeah, clear skies = starry, starry night