I've come back to Solar Winds maybe once in the past 20 years, and replayed SC2 about 4 or 5 times since UQM was released.
Was looking forward to the next instalment but the quagmire of legal issues, divided fanbase, etc, has really left a sour impression on the future of the franchise for me, which is sad given the world TFB created initially.
Solar Winds Galaxy is solid too, but not as engaging or as interesting of a story line.
UQM is definitely way more complex and involved. I remember dedicating days to it just to end up losing because of the deadline which I found pretty frustrating.
The first time I played through I lost all my landers a few times and wrote off those rich planets as impossible and didn't keep track of where they were.. then when my landers became better able to navigate the seismic / weather incidents forgot where they were. Now since I have Forbidden Plot Knowledge I can just jump right to the part where I have all the tech I want and am nearly unstoppable right away.
As a 12-year-old kid (or thereabouts), I remember playing another DOS space shooter/RPG called Solar Winds, which I remember having a reasonably engaging shareware episode. I tracked it down later as an adult and played the full release and the sequel, and both felt really rushed and fell well short of the world that the shareware version offered. It was definitely an experience that didn't live up to my childhood memories.
On the other hand, I didn't play any of the Star Control games growing up, and so had no nostalgia for Ur-Quan Masters when I first played it around 2018 or so as a middle-aged adult. The game definitely holds up today, and even though the combat can be frustrating, the game's heart and character more than makes up for it. Even the grindy resource collection aspect is oddly addicting.
It's a shame what became of the Star Control franchise since. :(