I don’t know much at all about the invasion side of things. I’ve tried the Watchdogs of farron for a bit to see what’d happen but never got anything, got summoned as a defender for Aldrich faithful 3 or 4 times but mostly people who were running around the area for funsies to kill invaders.
I did get invaded by a farron fellow though, once. I think most people are really just not playing while embered up, I rarely am. There should have been some better incentives to be embered if they wanted people to use it I think. Any time I am embered though I do get invaded and I’ve killed all but one of them.
As for duel meta it’s alive and shifting over the time I’ve been playing, when I started I came up against almost only ultra greatswords. People were using the fume, Lorian and moonlight greatsword. But I also ran into a mage every once in a while and I’ve lost to almost all of them, partly I’m sure due to inexperience but they were clearly good at what they were doing and took great advantage of my mistakes.
Recently I’ve seen, what I’m told is, an old DS1 strategy of using light parrying weapons like daggers, cesti and bucklers and once you’re parried they switch to a UGS or great axe for the riposte attack. Which I think is kind of BS because that kills you outright in most cases.
But I’ve seen people using spears/polearms, rapiers, dual swords, straight swords (of course), axes, spells and all sorts of weird combinations to greater or lesser effect. It’s been a lot of fun.
Edit: I think the main issue with Farron is that it’s so far away from a boss fight no one is going to enter the place embered and you have to fight an outrider knight to get in. The farron area does have 2 bosses IN it but they also open the path to new areas so few people are going to turn back right away. I did turn back after killing the crystal mage and got invaded instantly, not that he got anything out of it.