BMW has not had an easy time with its new 7 Series.

Since its launch in Australia in 2002, the luxury limo has not been moving out of showrooms with impressive speed - largely due, it seems, to people finding it difficult to come to terms with the styling.

The 7 Series is, to say the least, a challenging car to look at. It moves so far away from conventional expectations that it exists in a sort of limbo state as-yet undiscovered by car-buyers at large.

It's true that of all things concerning a car, styling is the most subjective subject of all. One man's meat may be another's poison, but it appears BMW may have trod too bold a path in attempting to draw new visual guidelines in car design.

In the short term this may all seem rather unfortunate but, as the big BMW moves into its second year on the market, the test will be to see whether the company can convince buyers that it represents a good investment as well as the best, in terms of sheer technology and capabilities, that the industry is capable of producing.

There has never been any question, right from day one, that the 7 series is an incredibly accomplished car.

Its road-going abilities stand out in the class, the packaging, even in short-wheelbase form, is competitive with its arch rival, the S-class Mercedes, and the equipment levels and pricing are spot on.

And the 7 Series remains true to the BMW edict that all cars with the spinning propeller symbol should contain a basic essence of sportiness. If you can imagine a two-tonne luxury sedan with undertones of athleticism, then you've pictured the current 7 Series BMW.

Speaking of two tonnes, an interesting question to pose when you're next talking about 7 Series BMWs, is how well the "base" V8 used in the 735i model copes.

For the size of car, it's not a large engine, although the power figures are none too shabby. No less than 200kW and a quite astonishing 360Nm of torque are produced from its 3.6 litres, both at relatively reasonable rpm.

But because you are talking about a weight approximating that of a full-size 4WD vehicle, even in the 10kg lighter (than the 745i) entry-level model, the engine has plenty of work to do.

No, the 735i doesn't quite shred rubber like the 745i, which will reach 100km/h from rest in a rapid 6.3 seconds. Rather, the 735i sits back a dignified 1.2 seconds away, even though it will top out at a speed-limited 250km/h given a derestricted German autobahn.

A small benefit is that, on paper, the 735i shows some small benefits in fuel economy - which would possibly be more pronounced if BMW hadn't needed to play with the final drive ratio to give it some accelerative bite.

BMW's figures give the 735i a consistent lead over the 745i across the economy spectrum, but there's not enough in it to have any real meaning.

The 735i is priced comfortably enough below the 745i, and the sacrifices in terms of equipment aren't too monumental.

All the basic running gear is the same, apart from the smaller engine, although the standard wheels are a tiny 18 inches in diameter - they seem that way when compared with the 745i's massive 19-inch alloys.

Electronic active safety systems are essentially the same too, except the 735i misses out on the 745i's electronic dampers and self-levelling rear suspension.

But it does get electronic stability control, traction control, and dynamic brake control which keeps it tracking on line if the brakes are applied in mid-corner.

Creature comforts are appropriate for a $174,000 car, although you don't get the glass sunroof, or the cushy, multi-adjustable seats or electric rear sunblind seen in the $207,000 745i.

While the 745i you have to pay extra for heated or air-conditioned seats, electric-assist door closing or the fully-adjustable "comfort" rear seats.

Compensation can be found in the fact that satellite navigation, TV, air-conditioned front and rear storage compartments, car telephone, park distance control and a quality sound system with in-dash CD changer are all standard.

The interior of the 735i is every bit as cosseting as the 745i with the tang of full-leather trim complemented by some gracious use of real wood on the dash, doors and, in a bold stroke by BMW's interior designers, in a curved panel that wraps around behind the rear seat.

In truth, there's little chance 735i owners will feel short-changed.

The experience is so much like the 745i that only the driver is likely to notice. With all that wood and leather the interior is a sumptuous place to be and the seats are truly excellent in their ability to locate and hold passengers comfortably.

It feels a little more enclosing than, say, an S-class Mercedes, but the overall use of space is about the same. Which means that rear legroom is fine, but can easily be encroached on by greedy front-seat passengers - especially if your 735i has the optional reclining rear seats that require a little more leg space as they move forward.

Mind you, the rear-seat passenger is able lord it over the left front seat passenger, moving that seat forward or backwards via a control on the rear centre armrest.

The driver will need to come to terms with BMW's iDrive, meaning a few hours with the owner's manual are in store for a new 7 Series owner.

BMW believes it is simplifying the business of managing all the control systems confronted in a modern car and that may be so, but iDrive still seems to be anything but intuitive and some things, even changing radio stations, are best left to a reasonably savvy front-seat passenger.

The 735i, as we said, drives pretty much like a 745i, except there's not the surge of power, or the ultimate road grip experienced in the bigger-engined car.

The 3.6-litre V8 works manfully, but needs to make full use of the six-speed automatic transmission. Maintaining pace on a long uphill gradient will see the auto moving up and down through the ratios is a way that may be imperceptible to passengers but will undoubtedly catch the driver's attention.

The steering wheel controls for the sequential transmission mode are no better and no worse than those of other carmakers.

The ultimate grip might not be quite the same as that provided by the 745i's bigger wheels and more upmarket suspension, but the 735i nevertheless grips well and steers with precision, rarely feeling as if close to two tonnes of perambulating metal are being asked to change direction.

And the ride, as BMW mastered long ago in 7 Series past, is excellent.

Absorbent, quiet, yet well controlled and inclined to sit flat when pushed into a corner, it would be fair to say it's at least as competent as a Benz, yet has a quite different, sporty character.

And that sums up the BMW 735i. A little less than the 745i, but it's still the luxury saloon for the buyer who wants a bit of attitude. The looks provide the visual challenge, the chassis provides the sporting flair and the sumptuous interior provides the luxury.