KIA is taking a far more aggressive approach with its fourth-generation Optima mid-sizer compared with its predecessor not necessarily in relation to its sales targets, but more in terms of its positioning in the market.

Pricing now starts at $34,490 plus on-roads for the base Si it’s an increase of $3000 over the previous entry version, although Kia Motors Australia says the new Si carries a standard features list more in keeping with the now-ditched mid-grade model.

The flagship GT starts at $43,990, which is also a $3000 boost over the old Platinum sedan. The new range-topper now gets a spritzy turbocharged engine, though, and way more kit than the outgoing car.

There are a lot of rivals that start at a lower price point, but Kia has thrown a significant amount of standard goodies at both variants, including safety tech that it new to the range, in a bid to alleviate fears of paying more for a base Kia Optima than a base Mazda6, for example.

Notably, both the Si and GT offer wireless device charging, autonomous emergency braking, a lane-departure warning, adaptive cruise control, sat-nav, dual-zone climate control, a reversing camera and front and rear parking sensors as standard, among a number of other comfort features.

The GT is a $9500 step-up, but it gains a whole lot more (see New Model story) and, on balance, it represents good value.

The shock of the almost-$10k difference between specs is emphasised by the lack of mid-range option, and when compared with some mid-size rivals the Optima is good value. The problem will be whether buyers are ready to pay Mazda money for a Kia key.

In terms of design, the Optima is an evolution of the previous model, still a stunning looking vehicle in itself. From the rear there is more than a hint of Hyundai's Genesis flagship, and at the front it retains the Optima's classic look while moving it forward slightly, but retaining its sleek profile.

There are some fussy elements to the styling, however, such as the chrome strip that runs from the exterior mirrors over the door frames and ends at the boot join, and the weird little rear-quarter window that is misaligned with the roof panel makes for a messy C-pillar treatment. And we noticed a couple of minor fit and finish quirks, including a Kia badge on the nose that was ever so slightly skew-whiff.

Overall, though, the design works, but it is inside where the new Optima really shines.

Much has been written about the improvements to Kia cabins in recent model generation changes – the Sorento SUV is an excellent recent example – and happily, the Optima continues the upward trend in quality and presentation.

Genuine soft-touch materials, an appealing steering wheel, a well organised centre stack and simple to use controls help ensure a simple and elegant dash design which, incidentally, is angled 85 degrees towards the driver – a similar strategy to the one BMW employs.

In Si grade the cabin is bathed in black, but manages to stay away from dreary, with enough chrome or aluminium look touches to break it up. The cloth trim on the seats feels a little cheap, but they are very supportive.

Being the sporty variant, the GT gains a flat-bottomed steering wheel and leather accented sports seats with GT embossed on them. The no-cost-option red leather is a fabulous touch, and really breaks up the black. The brushed aluminium panel in the console is a classy addition, as well.

Potential buyers who dismiss the Optima thinking that a mid-size sedan might not offer enough space as a large car or an SUV had better think again, because the Kia – which has grown all key dimensions by at least 10mm, ensuring more cabin space – is big.

The sloping roof-line has no impact on rear headroom, even with the panoramic sunroof in GT guise, there's acres of legroom in the back and ample space up front, and while the big boot isn't quite class-leading in size, it is still massive and swallows more cargo than a Commodore.

Based on its drastically improved interior, the Optima is up there with the best in class.

Kia has also spent a lot of time and money to ensure the Optima is a much more enjoyable car to drive this time around.

We only had a very brief time behind the wheel of the Si and it was about 30kms worth of freeway driving, so a more detailed analysis will have to wait for a full road test.

The 138kW/241Nm 2.4-litre naturally aspirated four-pot is a revised version of the same engine from the outgoing model, and while it should offer adequate performance for most punters, it is most certainly not the choice for anyone that enjoys a more spirited driving experience.

For that, you need to pay the additional $9500 and hop into the GT.

The 180kW/350Nm 2.0-litre turbo-petrol unit is shared with sister company Hyundai's recently launched Sonata, and it has proven to be an impressive engine under the bonnet of that car. It maintains its appeal when matched with the Optima, too.

Zero to 100km/h is over in 7.5 seconds, and the GT feels brisk off the line.

It's not a hardcore performance machine – nor is it pretending to be – but the torque and power delivery is smooth and the six-speed Sports-matic automatic transmission is a perfect match, offering faultless gear changes at any speed.

The Optima GT's brakes offer excellent stopping power under pressure, and the rack-mounted electric power steering is sharp enough and nicely weighted.

Kia's Australian tuning team, led by former Toyota engineer Graeme Gambold, has again had its way with the Optima, re-tuning the suspension so it better suits the country's conditions.

There is some light body roll, but it had little impact. The Optima otherwise sits pretty flat through corners, and even performs better than the new Volkswagen Passat when tackling some of the sharper bends we encountered.

B roads are handled well, although some of the larger potholes were felt more than others, but overall, the local tuning has again been successful. The Optima is dynamically well ahead of the model it replaces, which offered pleasant yet forgettable ride and handling. This new version, at least in GT guise, is an engaging, enjoyable car to drive.

Another area of improvement for Kia was in the field of noise, vibration and harshness (NVH) suppression, and the efforts have been worth the hard work.

Very little road noise creeps into the cabin, and the engine is only really noticeable when pushed.

Kia's speed-limit warning and lane-keeping aids are intrusive at times, but can easily be switched off. The added safety gear is otherwise a welcome addition.

In terms of fuel use, we recorded 10.5 litres per 100 kilometres a little more than the 8.5L/100 official figure but unsurprising given it was pushed hard.

The ambitious Korean car-maker is not shying away from the new higher price point, with local company execs saying that they believe the Optima is as good, if not better, than anything in the segment. And there are a lot of great cars in the segment, too – think Ford Mondeo, VW Passat, Mazda6 and Subaru Liberty.

In GT guise, the Optima impresses, thanks largely to that sweet turbo, the localised tuning helping ensure great ride and handling, loads of standard gear and the high-end cabin. In Si trim it is less of a compelling argument, but Kia reckons that variant will be the fleet special.

Kia is taking big leaps with each new-generation model, and it is about time the badge snobbery that exists in the new-car market is knocked on its head.

Models like the Optima and the new Sorento prove Kia can produce top-notch cars.

Anyone in the market for a mid-size to large-ish sedan – or indeed an SUV – would be wise to put the Optima GT on their shopping list. It might just surprise.