I finally got around to trying the Scorpion, but even for settlement raids and surface markers, the Scarab seems overall better in most aspects, especially when it comes to long range combat.
Edit: it seems good at killing sentry skimmers, but you gotta get pretty close because turrets are so inaccurate
It’s great against Guardian stuff and fun if you’re with a friend and as one of you can drive while the other shoots. The Scorpion can also do pretty decent damage to ships.
However the Scorpion doesn’t have a Wave Scanner meaning it’s pretty useless for exploring or looking for resources on planets.
In short: Scorpion for combat, Scarab for everything else.
My preferred playstyle for SRV combat is to pick enemies off at a distance, so I’ll stick with the Scarab. I can see the fun in using it for multi-player stuff though. I have yet to explore guardian sites.
Plus salvaging in the scorpion is tough with only two inventory slots