Before I begin, I want to say I've put many many hours into duel/pvp servers, playing around with different builds and weapons, so please hear me out. I've been using the gross messer as my main weapon of choice since I started playing, and I want to share my knowledge to hopefully give the devs and some players a better understanding on the balance of the meta weapons as they currently stand. Currently I believe there are 3 meta weapons for duels, gross messer, boar spear, and claymore. Claymore is pretty balanced so I won't go into it. Gross messer, sure some can say it's strong, but I don't believe it's overpowered to the point where it needs multiple nerfs. Sure, say what you want about it being a spammy weapon with a long reach for a 1 hander, but a lot of people that complain about it, don't have good enough footwork and parrying skills (which take skill and practice to be good at) to beat a good messer user. The messer's damage is also right where it should be against half-plate users. Most people who build half-plate will be using a 2 hander, and in my opinion and experience, messer vs half-plate 2 hander build is right where it should be as far as balancing goes. If the messer is nerfed more than it has been already, it will be completely useless against any half-plate user, especially if they use 2 handed weapons, as they do a lot of damage already, the only circumstance I believe the messer is "overpowered" in, is against un-armored opponents. Now I will talk about the boar spear, say what you want, but I've used this weapon many times in many duels and in team fights, and It's just downright overpowered. It is only 2 stones in weight meaning it only requires 20 strength to wield, as it stands right now it is currently NOT parryable by any weapon, it can do a maximum of around 45-50 in one hit (That's one third of my health in one hit) and hits consistent 30s-40s. In my opinion, those are the overpowered aspects of it. I've fought many great boar spear users with a gross messer, and I can say from experience, to beat a good boar spear user with a gross messer, you have to have amazing footwork and timing. One of the biggest complaints I hear from boar spear users about the gross messer is that it's too spammy, however, first of all to get close enough to a boar spear user to combo them, you have to first, dodge their attack (which is hard against a good user), dodge their hit and run attack (which is even harder), then if you make it close enough to them unharmed, they can easily just parry you allowing them to get an easy hit, now this is mostly applicable to duels, as in team fights you would rarely have to chase down a boar spear user alone to that extent. I hope this gives some insight on the meta weapons as they stand, and my thoughts from my many hours of experience of pvp.
TL;DR: Claymore - Balanced. Gross Messer - Way less OP than people make it seem, it's strong, but doesn't deserve multiple nerfs in a row. Boar Spear - Straight up overpowered. Takes a ton of movement skill to beat a good b spear user.