Small restaurants are easy to fill, and customers like that. Dining in an otherwise empty or undersubscribed restaurant is a discomfiting experience. What does the rest of the world know that you don’t?

But when restaurant projects on a grand scale work, they are exhilarating, serving up big dollops of contact with the human race at its most sociable. If you’re a solitary type who craves rural landscape undisturbed by human presence, a place like Sugo isn’t for you. But if you enjoy bathing in the recreational energy of humanity, is a lot of fun.

And it’s hard to imagine a better location for Sugo than in Charles Rennie Mackintosh’s Lighthouse Building, that 24-carat gold artefact in our architectural patrimony. I love this corner of Glasgow, Mitchell Street, and Mitchell Lane, the latter a dark cosmopolitan lane, a location that might be a cinematic stand-in for the gritty back streets of Manhattan. 6pm on a Saturday night and the area is hopping: shoppers eating before heading home; early evening rabble rousers. And unlike Edinburgh, these are locals, not tourists. As we wait patiently at the bar- you can’t book- we instantly see that talk of ‘peak’ dining times here seems pretty irrelevant. Sugo hit the ground running and shows no signs of let-up.

So much that Sugo does is theatre, but theatre in the public interest. From our table we can just about see the chefs working away in the pasta workshop- Italians would call it a ‘laboratorio’- kneading, rolling, piping filling into cut-out pasta dough, pairs of them stretching ropes of dough into long ribbons. It must be relatively cool in there, compared to the cooking station where a platoon of chefs stand over bubbling pots of ragù and sugo, plating up the dishes as the orders come in. The pressure is constant. A chef here has to be on it, no day-dreaming.

This much, Sugo’s look, its performance, could be copied and rolled out by an opportunist chain, but Sugo seems determined to do much better than that and there’s much that’s admirable about this mammoth operation. For starters, there’s the generosity that put this help-yourself bottle of reasonable extra virgin olive oil on our table, and the fact that the portions here are copious and affordable. I relish the extravagant pile of fresh Tuscan truffle that’s been grated on these butter-anointed noodles that are golden with egg yolk. Good heavens, the truffle actually smells of truffle. This isn’t the habitual taste- and aroma-challenged scrapings that need flavour enhancement from whack-you-between-the-eyes truffle oil. And then there’s the fact- bless them- that Sugo doesn’t overcook the pasta to suit Britain mores. I appreciate too that Sugo goes beyond the familiar, basic pastas, so you get not tagliatelle but tagliarini or tagliolini, and there are refinements within the spaghetti category, such as all chitarra, the slightly square-cut, ‘guitar’ string shape type.

An awareness that Italy is less a country than a conglomerate of regions makes for distinctive menu options: fettuccine with a spicy Calabrian n’duja & pork ragù treatment; squid ink spaghetti with a Sicilian accent in the form of lemon ‘pangrattato’ (crunchy breadcrumbs); squirmy, wormy bigoli with the classic, crumbly Venetian duck ragù. Our favourite is the Emilian agnolotti filled with veal, potato and cavolo nero in brown butter and thyme. They aren’t perfect- the dough is too thick so hasn’t cooked evenly in certain places, but the filling, and the sauce- a homely, intensely savoury gravy- cossets the soul.

This is a phenomenal tomato sugo on the rigatoni, but the traditional Ligurian pesto, potatoes, green bean pasta flops because the pesto isn’t up to scratch. I don’t blame Sugo here, just the variety, and dubious freshness, of the ‘fresh’ basil we can buy in the UK, which nearly always takes on a stale pond weed character the minute you bash it up.

Improvements? Sugo must learn that you don’t serve salads fridge-cold. It needs to heat plates and bowls so the food stays warm. Desserts so clearly have second class status here- routine cannoli, Mr Whippy ice cream etc- I wouldn’t bother ordering them. Still, Sugo gets an awful lot right.

Sugo, 70 Mitchell Street, Glasgow

Food: 7 and half/10

Service: 9/10

Atmosphere: 9/10

Value for money: 8/10