As someone who mains shield because I like the ability to say “Actually, I’m not being shot at the moment”:
Shield has outsized utility due to the Ogryn’s low toughness and giant hitbox- it’s not that it’s outrageously good itself, due to the downsides… it’s just the only reliable tool for covering a massive glaring weakness built into the class.
It’s a viable weapon, outstandingly so if you run with someone who can take advantage of the fantastic control it offers- one of my most frequent partners is an Eviscerator or Thunder Hammer zealot, and they’ve learned to check the floor in front of me any time they hear a crusher callout. It also synergizes well with the popular veteran tactic of firing into the horde, since it can create a nice neat pile of bodies to your left waiting to catch an insurance bullet.
I feel like one of the reasons it’s so in vogue to dump on the shield is that it gives you more options for coming out of a bad situation or imperfect play intact, so by performatively deriding it, these players are showing that they are skilled enough that they never make mistakes, are never caught in the open, never have a dense horde around them while a crusher is coming in with an overhead. It’s theatre… but like the genuine athleticism at the core of pro wrestling, they still make some valid points.
For all that it offers unique options, the maul and slab shield is undeniably undertuned as an actual weapon. They gave it downsides, and I think that’s reasonable… but they went overboard. Shove doesn’t fling the shield to the side like in Vermintide, so that’s nice… but if the impact is going to be on the mild side, the followup attack shouldn’t be dropping your guard. Vision is too obstructed, baseline move speed/dodge/sprint reduction is too severe, and the damage, particularly on the heavy attacks against Maniac armor type, is just inexplicably low.
I think it’s the performance on the heavies that sticks out the most. The feel of them is excellent; there’s a nice, meaty crunch and things go flying… but the first one is either too slow for the damage it deals or too weak for its wind-up time. I’d probably go with the latter; it’s a haymaker to the center of the screen, with a very narrow hitbox for a Relentless-type attack. It should be doing a little more damage baseline, and MUCH better damage to Maniac armor. Mutants can’t be staggered, so all that force still needs to go somewhere. A wider hit cone and better damage vs. carapace would be nice, but a narrow hitbox is a natural downside to a thrust/straight punch, and poor armor penetration is a natural downside to a diffuse striking surface like a shield. I can live with those as logical weaknesses if the illogical weaknesses are addressed.
The second heavy comes out at a much more reasonable speed, but… guys. It deals less damage than the light attack. It’s got better cleave and more stagger, but you “pay” for those with the charge time; the base damage shouldn’t be worse on a heavy than a light when they’re the same attack “type”.
TL:DR- the shield is a unique weapon in that it allows you to offset the Ogryn’s inability to use cover, the explicit traits of the weapon are undoubtedly present in the form of a strong defense and good crowd control… but it has real and significant downsides that keep it from being broken and may actually go too far in the other direction.