I'm not sure I've ever run across the term "source port" before, but it sounds kind of like what has happened with Transport Tycoon Deluxe, which has been completely reverse-engineered and rebuilt into OpenTTD. From there, the community has added uncountable features and fixes, all while retaining the basic gameplay of the original. In general, I try not to use anything that may exist in a legal grey area, but in situations like OpenTTD, where the original seems largely abandoned and forgotten, I'm more open. I quite enjoy OpenTTD, though I haven't updated my version in quite some time.

I would do the same if a similar community were to recreate and improve Star Trek: Birth of the Federation. I have always wanted a better version of a Civilization-style Star Trek game to play. There is a relatively recent one I forget the name of that mostly fits into that category, but running it is beyond the capabilities of my ancient computer.

I have run into this as well. When other changes are made, I will consider all aspects. Most often, I am willing to live with other changes in order to use the bugfixes, as long as the other changes seem to fit the game without changing anything fundamental. That being said, I do prefer the modular style of bugfix mod. I know I have used a number of those for games, but I can't think of them specifically off the top of my head.

The Skyrim one is one I'll have to consider someday, when I replace my computer and can actually play it. The two examples you cite for it probably aren't dealbreakers for me.

Like I said above, I prefer this kind of modular fix where you can pick and choose, but I'm enough of a realist to know that more often than not I'll have to take everything or take nothing. Generally I come down on the side of just being grateful a bugfix exists so that I have the chance to MAKE the choice; in gaming I can think of few things worse than discovering a game-breaking bug that has never been fixed.

I would argue that quite large, fundamental changes to a game are possible with mods. For example, Nehrim for ES: Oblivion or the mod for Hatred that turns it into first-person perspective.

It's definitely possible that mods can make the difference between a game I don't want to play and one that I do. I find vanilla Oblivion borderline unplayable with its broken systems; however Nehrim is much more enjoyable. Apparently, Pathfinder:Kingmaker is much better with mods as well.

I think it really depends on the game. I always take a look at what mods are available for a PC game I am considering playing - what the biggest issues are with the game and what mods are available to fix it.

Firstly when I saw the title of this thread, I thought it was forum mods and that this thread would be a compilation of threads where people have raised issues and forum mods have said "We're aware of the issue and we're working on it". Of which there are several outstanding. Maybe there should be a thread dedicated to that although I haven't put in the work to make it happen.

I rarely use mods that affect games in a moderate way. I usually want either minimal mods (quality of life, single feature change) or I want maximal mods (total conversions, feels like a completely different game)

Other games with (an optional) roleplaying component, there is more scope. For example CK3 has event packs including regional situational events. CK3 is a skeleton of a game still so there is so much scope for modders to fill in the gaps.

I guess for me, I think of it like this.

Many games these days are not finished properly, and so a mod can add what might have been part of the game if it had been finished properly.

And certainly we know of many games, that remain riddled with bugs, because they were never fixed.

Sometimes issues or at least major ones, can be fixed by something like a Community Mod, or at least improved.

But for every benefit Mods might give, you would have to say the majority probably don't really add much and may even detract from the game.

So mostly it is a personal perspective thing.

I wouldn't be counting on mods in most cases, to fix things that are inherently wrong with a game.

But maybe if it was for something like saving your progress in a better way or reducing the level of difficulty that some devs get anal about.

Some games for sure are ruined to a fair degree by bad choices made by devs. If a mod can improve that, then it can be well worth while. It may be that a bad choice was dictated by running out of money or financial support.