Much study has been done on the humble restaurant chair, with one researcher claiming that resting your bottom on a broader, more expansive chair leads to a greater feeling of personal power.

My personal research is similar: the more comfortable the chair, the more steaks on the menu.

As evidence, I submit the large, comfortable, leather-bound and padded dining chairs at 6 Head, the first of the new names to open in the massive $32-million redevelopment of the historic Campbell's Stores in The Rocks.

Once you're in one, there is nothing you can do except order a grain-fed 300-gram Mayura wagyu rump, or a dry-aged, grass-fed T-bone from Collinson & Co, and sit it out.

Stay seated, also, for a leather-bound wine list that includes dedicated Penfold back vintages and Bin 707 collections and offers the 2010 Rockford Basket Press Shiraz by the glass for a mere $100 ($480 a bottle).

Named for the six head of cattle brought with the First Fleet, 6 Head is clearly set up to be the flagship of the Seagrass hospitality group, and Money Has Been Spent.

Callie van der Merwe of Design Partnership has worked within the magnificent framework of the 1839 warehouse, with its hand-sawn timbers and soaring sandstone walls.

Temperature-controlled cabinets act as art installations holding wine and dry-aged cuts of meat, and the woodgrain tabletops – some a single tranche across the trunk – are as solid as butcher's blocks.

Another installation of knotted hanging ropes from artist Melissa Carey softens the sandstone and also references the First Fleet, with a single knot for every one of the 1500 people on board.

But that's not why I'm here. I'm here for the Collinson & Co tomahawk steak, a massive rib-eye on a long, glorious arc of bone, weighing in at one kilogram. It's $150, so I've brought a pal, but it's a good reminder that a ridgy-didge, dry-aged, grass-fed steak is a great luxury.

Given the heritage site doesn't allow open flame, the custom-made grill does a top job of getting a good crust on the outside, and the wreaths of rich fat throughout are like a sauce in themselves.

It's precisely cooked between rare and medium-rare as requested, and carved expertly and with due ceremony at the table. I have to say it's quite the experience.

There's all the usual steak house faff about choosing sauces (which I don't believe are their strong point – go for the mustard instead), and a crisp salad and chips are thrown in.

Other steak-housey options from exec chef Sean Hall's menu include wagyu burgers, slow-cooked short ribs, lobster tails with herb butter, and a $120 seafood platter, but if you have the Tomahawk, you don't need anything else.

That said, a kingfish ceviche ($24) is well-played with chilli, black lava salt and garlic creme fraiche, and a gnarly, rustic, hand-chopped lamb tartare ($25) is excellent, presented under a smoke-filled glass dome and strongly seasoned with dill pickle, mustard and capers.

The burger I try – wagyu and bone marrow in a brioche bun with onion rings ($32) – is dull and dry; but a sugared puffball of a doughnut ($19) with creme anglaise, fig sauce and strawberry powder is light and yeasty.

Big steaks, big reds, big heritage building, big harbour views; it's easy to know where you stand at 6 Head. Or, more correctly, where you sit.

The low-down

Vegetarian Limited, even for a steakhouse. One burrata starter, one "farmer's pie" main and six vegetable sides.

Drinks Vast list of 250-plus local and international wines, with Coravin allowing some pretty exceptional wines by the glass.

Go-to dish 1 kilogram 280-day aged, grass-fed tomahawk to share, $150.

Pro tip Tell summer to hurry up; that terrace has sparkling harbour views.

Terry Durack is chief restaurant critic for The Sydney Morning Herald and senior reviewer for the Good Food Guide. This rating is based on the Good Food Guide scoring system.