The way I would like to see tag spam addressed is for every community to have a strictly enforced list of allowed tags.
Since every post would be limited to the tags allowed by the community it is posted in: they wouldn’t be able to spam more than a handful of tags.
I found that it depends on the game and how it’s set up. I’ve used the steam controller on a lot of games and it worked well.
As you’ve considered it really comes down to how it’s configured. And you have to reconfigure it for pretty much every game you play. And steam itself doesn’t provide you with good configurations most of the time.
I love the controller but wouldn’t recommend it because of the amount of time it takes to make it work well in each game.
A PS4 controller is just plug and play, and is what I would actually recommend to most people.