Putting all memes aside, from a neutral perspective, this weapon is pretty damn good! On a pure Strength build (RoF+3,Havels+3, Wolf Ring+3), due to its low weight, you can poise through everything expect a greathammer due to the heaviest armor you can use (only Astora is even lighter by 2 points).
All kind of greater weapons can be easily dealed with a mixup of 2H R1s, R2s, rolling-R1s and Stomp-R1s (play as unpredictable as you can get and they WILL ***** up their roll-timing at some point, buffed with a resin, 4 R1s will kill most opponents in the arena).
Due to their slow speed, fast weapons like straight swords are the best counters to UGSs, so switch to 1H and either use parries or an offhand heavy-infused caestus and mix-up R1s and L1s, a very good bait is also an R2 followed by either L1 or parry.
Overall, the heavy-infused Zweihander with full Gundyr's is one of my favorite setups, my success-rate in duels is easily over 75% in duels and spears of the church-fights, even in invasions it's viable due to gank-spank-capabilites. Giant Dads heritage is real in DS3 and more fun to play as in every previous game. With easily over 50 poise, you can tank through everything, including almost every other UGS, standing victorious in shredded parts of dexfags and quality casuls, pointing down at their so-called meta-weapons most of them never mastered, because they never had to.
Washing Pole with Armor of the East - more like: Armor of the DECEASED!