For me - I expect problem with gamebreaking bugs. People are not going to like "you can't do anything with that" or "you must apply this weird workaround".
I tried reporting bugs, making reproducible saves making easier to fix them, I made that poll in attempt to find the worst ones.
I stopped playing DF some time ago because it turned into endless workarounds for various bugs. I have no bug problem with UI and interface (though it is horrifying and really should be fixed).
I though about playing DF again, but I checked now my old "What is the worst bug in DF?" poll (
http://www.bay12forums.com/smf/index.php?topic=111051.0 ) and over six years later I checked following top bugs (over 2% of votes)
http://www.bay12games.com/dwarves/mantisbt/view.php?id=5895 - fixed
http://www.bay12games.com/dwarves/mantisbt/view.php?id=5991 - fixed
http://www.bay12games.com/dwarves/mantisbt/view.php?id=535 - reported in 2010, unfixed
http://www.bay12games.com/dwarves/mantisbt/view.php?id=1582 - reported in 2010, unfixed
http://www.bay12games.com/dwarves/mantisbt/view.php?id=94 - reported in 2010, unfixed
http://www.bay12games.com/dwarves/mantisbt/view.php?id=5312 - fixed
http://www.bay12games.com/dwarves/mantisbt/view.php?id=2712 - reported in 2010, unfixed
http://www.bay12games.com/dwarves/mantisbt/view.php?id=1451 - reported in 2010, unfixed
http://www.bay12games.com/dwarves/mantisbt/view.php?id=2922 - fixed
http://www.bay12games.com/dwarves/mantisbt/view.php?id=412 - reported in 2010, unfixed
http://www.bay12games.com/dwarves/mantisbt/view.php?id=5097 - reported in 2012, unfixed
http://www.bay12games.com/dwarves/mantisbt/view.php?id=3190 - fixed
http://www.bay12games.com/dwarves/mantisbt/view.php?id=4552 - fixed
http://www.bay12games.com/dwarves/mantisbt/view.php?id=136 - reported in 2010, unfixed
http://www.bay12games.com/dwarves/mantisbt/view.php?id=33 - fixed
http://www.bay12games.com/dwarves/mantisbt/view.php?id=4230 - reported in 2011, unfixed
It is impossible to fix all bugs in any real software*, but decade old serious bugs are frustrating.
At least for me it sapped enjoyment from the game.
I know that Toady is not obligated to cater to me, but given explicit question I want to give my answer.
Though I see more fixed bugs than I expected, I guess that I should retry in six years - maybe second half of the worst bugs from 2013 will be fixed? Maybe I will update my poll once new version will be released, not sure is it worth doing.
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As far as I know, fixing bugs is not a high priority. And preparing reproducible save that may take hours of work is waste of time because it will be completely ignored (or at least there was no feedback to saves that I have seen, new version was released and save stopped being useful, with bug ignored for years). I realized that I am wasting my time that is probably not welcomed and switched to doing different things with my life.
I hoped that paid release to wider public means that some serious bugfixing happened/will happen, but for now I see no evidence of that.
Still, thanks for making DF! It was one of the best works of art/games/software that I have seen, and given that I obtained it for free I do not feel entitled to anything.
I just wish it had lower number of systems and features and more actually working system, features and interactions.
(endrant, sorry, six year later I am still flustrated - DF is so close to what I want and it still fails due to slightly different priorities)
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*there are rare exception like TeX, but it is as rare as politicians that are successful, moral, effective and useful at once.