I have 3 "complaints" with the game at the moment.. And this is based off 1500 hours of game play, these are starting to grate on me a little. So feel that I need to air them here, while we are all having a constructive whinge..
Performance needs looking at. This isn't a "it's badly optimised" comment because I don't think it is badly optimised. This is a comment that performance in late-game sucks, just like RCT3 did back in the day and just like Sim City 3000 did in the early 2000s; a symptom of this kind of game. But this doesn't inspire you to stick with a park as it dies very quickly. The performance fall-down has been getting progressively earlier as they release more DLC items too - obviously because it has to render and index more and more new objects than before. I think it needs a bit of a performance patch where some-one sits down with everything and sees if there is a better or more efficient way of doing things. I get that I describe "optimisation" here, so I get the irony of my statement. But this is more of them needing to sit back and take stock of what they NOW have to find efficiencies rather than saying that they were bad from the start.
Which leads me to point 2, still performance related. I reported many months ago, and again a week ago that guests in queues create lag. And the slower the queue or the more in the queue, the worse it is. If you have a park of 16000 guests and close / empty the queue of your rides, you can experience as much as a 50% increase in FPS. now, based on my investigation and my limited information, it seems that the guest collision and path finding may be at fault. It seems that guests in queues are still looking for paths to things that satisfy their needs that have declined while in a queue. But as they can't find a path because they are in a queue, they continue to recalculate constantly. Take them out of the queue and their path to that needs-satisfying location is clear.
And third; track rides throughput and demand cripples the game completely. It's not so bad in early game, but in the same 16,000 guest park (when it was at 11,000), I create a Hoax that had 1600 prestige; way higher than anything you can achieve with a coaster and I managed to squeeze just short of 9000 guests into the queue for it. All of the other rides had died in demand completely, the game slowed to a complete halt because of Complaint 2. Now, this doesn't take a mathematician to work out that this is not right. A guest will typically be in the park for around 300 to 500 real-world minutes. A guest joining the Hoax queue at it's max will get on the ride in 1,370 real-life mins. But yet, despite this being clearly rubbish, it's gone ignored. They have literally developed a batch of rides that are useless to any-one with big-park ambitions. "All" they need to do it adjust the track-ride demands / prestige to fix it.. This sort of leads into a fourth, which is the station load / unload situation. If they allowed simultaneous unload and load of stations, this track ride issue wouldn't be so bad. But that's another thread all together!
In conclusion, I think that these complaints of mine would be put to rest if the dev team acknowledged them and explained why they are like they are. I know Andy did a fantastic job of explaining some of the performance related stuff in the early days, so an update to this would be helpful - as for the other stuff, WHY is the station loading the way it is? WHY is performance suffering earlier with the more DLC's they load? WHY do guest in queues cause the lag it does? At least if we knew why, we could start to understand whether the complaints are justified or not.