Especially in lengthened version, the BMW 7 Series would make a far better limousine right out of the box than are most stereotypical Lincolns and Cadillacs after they've been converted.

Travelling in a 7 Series is a first class experience anyway, so adding more room and boosting the level of equipment takes that experience into executive privilege territory.

Among the upscale things you get – rear roof consoles with vanity mirrors, electrically adjustable and heated steering wheel and dual zone climate control. Move up to the longer car (for an extra $6,400) and you also get rear foot wedges (to provide a more comfortable leg position) and a 2-position memory for the front passenger's seat.

Move up to the 760Li (for another $67,600!) and you get adjustable and heated rear seats, ventilated massage front seats, rear controls for heating/ventilation and radio operations, and electronically controlled sunshades for all rear glass, among others.

All of which provides a great riding ambience for the largest BMW sedan, which makes it a kind of conundrum since it is one of the best driving sedans in the world (regardless of size).

The 750Li is 140 mm (about 5.5 inches) longer than its smaller sibling the 750i (the L stands for long, in case you hadn't figured it out), with just about all that taken up in wheelbase (138 mm longer). The resultant gain is primarily in rear seat room.

The ride in the 7 Series is exquisite and the longer wheelbase is useful in soaking up a lot of the undulating pavement you find in in-city driving. But get it out on a racetrack and it will put some sports sedans to shame, with its precise steering and suspension that keeps wheels planted and the cabin neutral. You wouldn't want to race a 7 Series, but it sure would make a nice single-marque racing series.

Power is provided by either a 360-hp 4.8-litre V8 (750s) or 438-hp 6.0-litre V12 (760). Both are equipped with BMW's double VANOS variable valve timing, which gives the car the power it deserves combined with some sensible semblance of economy (relatively speaking).

As we've found on past BMW automatic transmissions, the 7 Series' 6-speed automatic's computer takes its shift quality too seriously, causing apparent (and often annoying) lags in power delivery. Even controlling the shifts yourself through the steering-wheel mounted buttons doesn't really override the annoyances.

Another previous annoyance, the BMW iDrive central control system, is enhanced further to deal better with ongoing complaints. In the latest 7, the system allows you to control more features, but the peripherals have their own set of controls to make changing radio stations or setting temperatures much easier and safer. In the longer cars, rear passengers get their own iDrive control dial to control their entertainment system.

There is no denying the BMW 7 Series is big in what it is as well as what it does. Is it beyond justification? Not if you can afford it.