Personally, I prefer turn-based because I have literally all the time I want to make decisions. I mostly play strategy games regardless (and against an AI at that), but something like XCOM is a lot less stressful than Age of Empires because I don’t constantly feel like I’m falling behind if I take an extra few seconds to check something
Chapter Master: Adeptus Dominus
Essentially a free, fan-made 40k game originally made like 20 years ago by one guy who has since moved on. Now it’s a small team who drop semi-regular updates on github. Also, it runs on Linux