Just worked my way up to the survey mothership and it is SOOOOO COOOL.
It's an absolutely fantastic feel dealing with its unique defense systems and the huge multipart mothership itself, and it was as part of something I just randomly found and had to work through the probes and the ship up to find the mothership itself. Not a mission or anything. Basically everything that exploration is cool for
I guess I have mild quibbles with the encounter a little? There's too many of the probes in any given system, imo - was getting irritated with the number of minor, non-autoresolvable encounters. And the mothership itself was relatively easy compared to its defense force. (Have it spawn drones?) And the huge amount of flares chugged my framerate. But those are minor, relatively. Really felt like an accomplishment getting through this thing. ... Definitely had a homeworld-ish vibe, come to think of it.