We say The vast, seven-seat GL-Class is a car full of compromise.It's unwieldy and expensive but if its fits the bill you'll love it.Performance The GL-Class comes with 3.0-litre V6 224bhp petrol, 4.6-litre V8 and 5.5-litre V8 engines and all are up to scratch. 4-litre petrol offers power and economy. None are cheap to run but all are extremely capable.Emissions Fuel economy under 30mpg is not unexpected. Eye-watering CO2 emissions put it in the bottom two road tax bands, depending on the engine choice.Driving Since it's the size equivalent of a small house the GL is not the easiest cat to control, but it behaves itself around corners and the ride is smooth. City driving is difficult because if its bulk.Feel A little noise intrudes from wind and engines, but not so much that it's a problem. The car is supremely poised and comfortable over long distances.Space Size is limited by practicality - awkward access is limiting, but the load space is vast if you can figure it out. The seats provide more than enough leg- and head room. Not surprising for such a long, tall car.Equipment Alloys, climate control, cruise control et al. Leather upholstery, lashings of wood and plenty of extras on higher trim levels. An optional off-road package has a range of features to help on more rugged, challenging terrain.Price It’s a Mercedes and this means residual values will be strong. That’s the good news. The bad news comes in the shape of plus-£70k prices and big running costs. At least you get a lot of car for the price.Quality The Mercedes GL-Class feels premium inside the cabin with plush materials and a solid build quality. Reliability is good, which is a bonus considering servicing costs.Safety The driver and passenger are incredibly well protected with all manner of safety kit including whip-lash protection head rests.Pros It’s big, practical and capable of carrying seven in a luxurious setting. On the road it is refined and the Mercedes badge and build quality ensures desirability and residuals impress.Cons The GL-Class has massive dimensions which can be tricky in tighter spaces. It is also very expensive to buy and run.Alternatives Land Rover Range Rover