Still a new player from April (compared to most anyway) - purchased 5 DLC and enjoyed them - to finding that my below min requirement PC (CPU) was handling performance of the game in Med galaxies, 0.25 habitable ridiculously slow at year 2350+ (seconds per day). No more than 9 AI, 2 FE and maybe 1 Marauder.
I never bothered to see a game out apart from the first couple. I also took part in that save game floating around that is in observation mode at late game on a Large or Huge galaxy I think - and found a year took 22 minutes(woe is me).
This game would have been the push I neeeded to upgrade my PC (MMOs and FPS games gone off the boil for me, so arn't important) but as it turned out, everyone in the community was like "don't", atleast for Stellaris a lone, its still crappy at late game. Now I have a work laptop (10th gen i5 entry, budget end), I'm sure I'll feel a difference but by all accounts only to the level that most people are clearly unhappy with.
That all being said, until recent playthroughs I hadn't given a lot of attention to AI and other well documented problems, I had even thought the AI going back and forth between systems was in actual fact a strategic thing but it really isnt. In fact 'gaming' the AI seems easy and it doesnt go for the 'kill button' when it has the chance too. And the bugs with fleet manager.... and what is going on with the auto build buttons? As a new player I was using them, not having any idea what I was doing. But had I realised how buggy they are, I would have left a sour taste in my mouth and a bad impression of what otherwise looks visually polished game. People were telling me in Discord to immediately not use them or that they had no idea what buttons I was talking about. Is that what you want as a new player experience (auto build specifically - it's surely meant to be an initial crutch for new players to use whilst learning a vast game)?
In the end and until the latest dev diary, I had stopped playing Stellaris back in early August. with around 230 hour play time because of everything but mostly performance problems. So I'm hopeful that the latest dev diary and MrFreake responding here is purposely saying "We now have something to tell you and respond with". Without being a prior PDX gamer, I dont have preconceived ideas about PDX to know about other than this forum, so I'm inclined to give them the benefit of the doubt. And if it proves fruitful, I will be buying Megacoorp/Federations and even the plantoid pack. (Too frugal to buy the new DLC...)
I don't doubt there are probably hundreds/thousands of players in a similar perspective to mine, so fingers crossed whats coming will make a good impact.
