This doesn't have anything to do with the +2/+3 argument per se, but I wanted to mention that I actually use hawl to destroy gliscor, physically defensive or not. Often the only attacks gliscor runs are knock off, which will activate your unburden, or earthquake, which you're immune to. The only thing that could really beat hawl is a well-timed toxic/protect stallout. But usually even if gliscor tries to toxic stall, all you have to do is predict his protects and SD in his face on them, and eventually you'll be OHKOing him, and one or two more pokes, depending on your remaining turns of toxic to KO you. And even if gliscor manages to toxic stall you to death while he toxic heals behind his protects, you're likely going to do enough damage to allow another pokemon to roll through gliscor immediately afterwards, even ones that usually wouldn't have a chance, such as scizor. Either way, hawl has contributed to the battle in a big way, removing or weakening a significant threat.So I know most everyone prefers Sitrus berry on the SubSD set to fair better against sand and is just generally useful in a pinch, but is there any merit to a Liechi berry? If you have a more aggressive team, or one that can effectively remove Ttar or Hippo It could be useful in a pinch. It helps against opposing aggressive or hyper offensive teams which might not give you a chance to set up an SD too, since you activate unburden and get an attack boost at the same time.
I'm going to be running some calcs on the merits of having +3 rather than +2 attack, will update this post in a bit.
Calcs:
+3 252+ Atk Hawlucha High Jump Kick vs. 252 HP / 252+ Def Skarmory: 261-307 (78.1 - 91.9%) -- 31.3% chance to OHKO after Stealth Rock
+2 252+ Atk Hawlucha High Jump Kick vs. 252 HP / 252+ Def Skarmory: 210-247 (62.8 - 73.9%) -- guaranteed 2HKO after Stealth Rock and Leftovers recovery
+3 252+ Atk Hawlucha Acrobatics (110 BP) vs. 252 HP / 252+ Def Slowbro: 262-310 (66.4 - 78.6%) -- guaranteed 2HKO after Stealth Rock and Leftovers recovery
+2 252+ Atk Hawlucha Acrobatics (110 BP) vs. 252 HP / 252+ Def Slowbro: 211-249 (53.5 - 63.1%) -- guaranteed 2HKO after Stealth Rock and Leftovers recovery
+3 252+ Atk Hawlucha High Jump Kick vs. 248 HP / 136+ Def Mandibuzz: 352-415 (83.2 - 98.1%) -- guaranteed OHKO after Stealth Rock
+3 252+ Atk Hawlucha Acrobatics (110 BP) vs. 248 HP / 136+ Def Mandibuzz: 298-352 (70.4 - 83.2%) -- 62.5% chance to OHKO after Stealth Rock
+2 252+ Atk Hawlucha Acrobatics (110 BP) vs. 248 HP / 136+ Def Mandibuzz: 238-282 (56.2 - 66.6%) -- guaranteed 2HKO after Stealth Rock and Leftovers recovery
+2 252+ Atk Hawlucha High Jump Kick vs. 248 HP / 136+ Def Mandibuzz: 282-333 (66.6 - 78.7%) -- 31.3% chance to OHKO after Stealth Rock
+3 252+ Atk Hawlucha Acrobatics (110 BP) vs. 244 HP / 0 Def Gliscor: 322-379 (91.4 - 107.6%) -- guaranteed OHKO after Stealth Rock
+2 252+ Atk Hawlucha Acrobatics (110 BP) vs. 244 HP / 0 Def Gliscor: 256-303 (72.7 - 86%) -- guaranteed 2HKO after Stealth Rock and Poison Heal
+3 252+ Atk Hawlucha High Jump Kick vs. 252 HP / 212+ Def Rotom-W: 325-384 (106.9 - 126.3%) -- guaranteed OHKO
+2 252+ Atk Hawlucha High Jump Kick vs. 252 HP / 212+ Def Rotom-W: 261-307 (85.8 - 100.9%) -- 87.5% chance to OHKO after Stealth Rock
So Liechi berry? Not a significantly good investment. Against the premier physical walls of OU you're not changing much (keep in mind I used the specially defensive Gliscor, physically defensive gliscor laughs at you, as does Landorus-T and defensive Gyarados.)