Governor, governor, governor. One of the least-understood cards, I think. Certainly by me, but also I think in general.
The consensus is very much as Robz888 points out in the article, but... I am not at ALL convinced that this is even very close to the right way to play. Indeed, I think as just a big money enabler, it's not that great at all. You use it largely for gold/silver, and well, those silvers you give them are pretty useful. Especially if there's some other 5-cost that's nice for them. Or a 4-cost even, as a defensive trash for points. Those are huge by the way. They make all kinds of alternate-victory cards very relevant. Particularly, you look at silk road, gardens, island - ways to trash your zillion extra silvers defensively.
But, look at how governor for big money compares against more conventional BM strategies. Well, you're giving them silvers, which is actually a big deal - it lets them get more of their terminals, which they may indeed need to do in order to compete with you, but if they're paying attention, they will do. They use your silvers to quite an advantage, particularly since Gov player is using lots of time buying governors, which only help you to get things that help you to get provinces for most of the game. The other player is buying cards which directly get them to provinces. Ad indeed, I am not nearly so sure that you should always prefer governor to gold, for these decks anyway. Perhaps the first one or two, but.... Really, for governor player to win these games, they really need multi-province turns. And usually, because to get this, you need to use lots of card-draw, they'll be able to nail a province for sure. Which means you need multiple multi-province turns and/or 3+province turns. Also, because these games tend to be shorter, you should green sooner. In fact, I find the games are often so short, that it's not so worth it. For big money, it's just a mediocre card, maybe even at best. But it does lead to shorter games, so one or two turns of shuffle luck can mean quite a bit more. I guess the big thing is, look at how many governor plays you have to do to get enough golds, then you need to be able to draw enough to get golds AND governors in your hand, AND have enough money to buy another province at the end...
However, there's more here. It's potentially quite good in engines. You can use the trash option to get some decent components at the right price points. Indeed, it's sort of like develop in that it's in some ways quite dependent on what's available at different price points. I guess swindler here also has some similarity. But more, the cards option is potentially very strong. There are a number of cases where you can use it with RELATIVE impunity. I mean, the first one is the discard attack as is stated, though you do want to be a little wary here (also, note that moat is a REALLY good defense to this - you're having me draw so many cards before attacking me, I have a good chance of drawing my moat. And even if I don't play it... it's defending like 5 of my cards now, instead of 2; well worth it), as a best 3 cards out of 8 or something is a lot better than 3 out of 5. But another situation is where you're playing against library/watchtower/jack - the cards don't help them much. More commonly, you're playing against someone who's drawing their whole deck anyway - no big deal then, if you make them do it a little faster. Still more commonly, they have no source of extra buy/gain. Sure, now you're guaranteeing them a province on their next turn. But if you can mega-turn, well then who cares? So what this option loves, and the card itself loves to some extent, are ways to mega0turn. Plus buys and gains that aren't limited to by cost (so with highway also works, but I'm largely thinking of HoP here), cards that love handsize (forge is nice, bank if you've got buys) - some way of making an engine, you're good. Also, in such games, you often have mirrors, right. And in this case, the gain option is more powerful - you can use the golds, to remodel if nothing else, much better than they can use the silvers. What will they do with the silver? I guess remodel it into governors. So, it's weird, governor sorta works better in non-mirrors, sort of how tribute works best in mirrors.
But I guess the thing I'd say most is that, while you're right to be somewhat wary of using cards too much, as that's a pretty nice benefit to your opponent, I think people may have learned that lesson too well, though maybe the top top players less so.