I'm used to managing the AI on superhuman, but the AI here seems to make it considerably harder, at least initially. Doesn't help that I've been forced into night missions. Seems to be higher probability of aliens being close to Skyranger and facing it (last one on purpose I read), and while aliens seem to wonder around aimlessly by themselves doing whatever they might be doing in the original game, in openxcom they seem to be more likely to have a friend close, and actively attack X-Com soldiers. I'm hoping I will like this change, just have to find how to cope with early missions first 
The original had a bug that the difficulty reset to Beginner after the first mission.
You've probably been playing on Beginner for all those years and now play Superhuman for the first time in OpenXcom
Probability of aliens being close to the Skyranger is the same as in the original.
Probability of aliens facing the Skyranger depends on the difficulty (at least in OpenXcom, not sure about the original), so playing on Superhuman increases aliens facing the craft.
The AI decision making is 98% identical to the original. Even with all the imperfections. Intentionally.
The remaining 2% are things that were impractical or impossible to replicate.
But I know quite a bit about the original game, and there's quite a lot of resources on the original game in ufopedia for instance, so I found the wiki page on differences with the original game a bit lacking. Could it be possible to flesh this out a little?
For a casual player, there are practically no differences between the original and OpenXcom.
For a developer or a guru, there are conservatively speaking hundreds of differences, realistically thousands.
It would take forever to describe all the differences.
And deciding which differences are worth describing and which are not is equally futile effort.
For instance, I've noticed that I've yet to start a research progress where I get known progress from the start, which was 1/6th chance in original game. Why? Is it just hidden at the start to avoid people reloading to retry? Or have limits for known progress changed, or has random part of research time been changed, so you never get down below 67% of initial value?
Was a bug.
It's nice that you have removed the 80 item limit, but it doesn't really sound like a bug that the Skyranger has finite storage for gear. Certainly worth mentioning on its own, and possibly also being able to still have the limit. When the content counts against base storage, you get less storage than you had in the original game. Is there any limit at all for what you can bring in the Skyranger now? Item count limit? Item weight limit? A bit strange that items in your Skyranger is removing space from the general stores, though I guess it's a practical workaround to a too restrictive 80 item limit.
By default, there is no limit.
But there is a built-in mod in OpenXcom, which you can use to restore the 80 item limit from the original.
Go into the MODS screen and look for the "Limit Craft Item Capacities" mod.
Research rollover. It sounds like a bug that you get to use all the scientists for a new project, especially as it happens only if you choose a new project that is later in the order. But maybe you should get to reuse the extra resource capacity you didn't need? In the original game, you wasted half the scientists on average but if you chose new project on random you'd have a 50% chance of being able to use all of them a second time, so if you didn't try to take advantage of it in particular, the end effect would be that you would reclaim about the same amount that you had overflowing. I'm guessing that you don't get rollover of either required or extra research hours used in openxcom. Might be closer to the original game to let overflow research roll over, but to any new project you assign them to. Does anything overflow in openxcom? Not a big deal, but as it is debatable what is a bug and what is a feature, and there might not be one single obviously correct way of getting around it, it would be nice with some more info.
There is no rollover in OpenXcom.
It was a known bug of the original and it was not replicated in OpenXcom.
Of course, there is always at least one person alive that says it was a feature... but majority wins.
Also I didn't find a list of known issues with openxcom, but it has been dead stable for the testing I've done so far, so I'm hoping that means there's none
There are a few known issues that are impractical to solve or which we are too lazy to solve.
I won't describe them individually, so that people can sleep well at night... and more importantly so that they don't annoy the living heck out of the DEVs.
And of course, any software more complicated than TicTacToe has bugs... that's a universal fact, and it applies to OpenXcom too.
If you find a bug, report it.
We're still actively fixing bug reports.
