Good things come to those who wait, and all that. We’ve had to wait a very long time indeed for Mercedes to bring us a rival for the BMW X3 – so by that logic it ought to be very good indeed.

And is it? To find the answer, here’s the range-topping 250 d AMG Line in a three-way shoot-out with the X3 xDrive20d and Land Rover’s Discovery Sport – which, Britain being Britain, will always be the one to beat in terms of sales alone.

The GLC certainly arrives with a strong arsenal. It looks the part, it’s handsome inside and it’s very well equipped. It costs more or less the same as the others, too – despite being usefully more powerful.

The Disco Sport tested here is the 2.0 TD4 180 HSE auto. So we’re looking at range-toppers all round, which means wall-to-wall leather, climate, cruise, 19” alloys, heated seats, power tailgates and rain and dusk sensors whatever you buy.

Only the Land Rover gives you a panoramic roof, however. But more to the point, it comes with seven seats. That puts a tick in an important box, making it a more universal family wagon – and, for short hops, an acceptable way for seven adults to get about.

The Disco is favourite for carrying big loads, too, though it’s interior is the least classy of the three. Here, Mercedes takes the crown with some gorgeous design touches – though these shouldn’t distract you from the fact that it’s the least spacious vehicle here.

It is, on the other hand, the quickest. With a handy slew of extra power and torque, it pulls strongly in gear and accelerates with verve when whipped. Perhaps surprisingly, however, the X3’s auto box seems smarter than the others’ – despite having one ratio less then either of them. That doesn’t stop the engine from being the loudest of the three, though.

Still, BMW drivers won’t feel short-changed for speed – though Disco Sport owners might. Land Rover’s wagon is set up well enough for a comfy ride, however, and it’s feelsome to steer, though the others exhibit better body control in corners.

In Merc’s case, this doesn’t come at the cost of a fidgety ride, but the M Sport version of the X3 tested here is too firm to either ride or handle properly on anything but a totally smooth road. You can order it with standard suspension at no extra cost, which is just as well because the other alternative is to pay £650 more for adaptive shocks – which seems a bit cheeky when the other two are just fine without any of that.

At least the X3 starts with the lowest price, though the Merc’s emissions score means it’ll be the cheapest to drive if yours is a company car. Dealer finance prices will make the GLC look like a good idea, too, though when everything’s considered it’s the Disco Sport that’ll cost the least to buy privately over a three-year period.

That’s one reason why Land Rover remains champion of the small premium SUV division after this bout, but by no means is it the only one. It’s the comfiest, best kitted and by far the most practical of these three. The X3 is a former champion and the GLC is an excellent addition to a high-quality market – but that just goes to show how good this Land Rover is.

BMW X3 xDrive20d

Engine size: 2.0-litre diesel

Price from: £38,590 (list)

Power: 188bhp

Torque: 295lb ft

0-60mph: 8.5 seconds

Top speed: 130mph

Fuel economy: 38.4mpg

CO2: 136g/km

Land Rover Discovery Sport TD4 180

Engine size: 2.0-litre diesel

Price from: £39,400 (list)

Power: 178bhp

Torque: 317lb ft

0-60mph: 10.3 seconds

Top speed: 117mph

Fuel economy: 35.9mpg

CO2: 139g/km

Mercedes-Benz GLC 250 d

Engine size: 2.1-litre diesel

Price from: £39,595 (list)

Power: 201bhp

Torque: 369lb ft

0-60mph: 7.7 seconds

Top speed: 138mph

Fuel economy: 39.3mpg

CO2: 129g/km