The Asus PadFone series has been around for two years now, and continues to be the only smartphone which can be docked into a tablet.
After the original PadFone in April 2012, Asus released the PadFone 2 later that year, and followed up with the PadFone Infinity in 2013. Last year, Asus launched the PadFone S.
The PadFone has always been at the top of Asus' phone line-up, with the Infinity originally retailing for $898.
However, with a number of handset manufacturers now releasing flagship devices at much lower prices, such as the OnePlus One and Xiaomi Mi 3, Asus has followed suit and slashed the price for the PadFone S, which retails for $449.
But to achieve this price, what compromises did Asus have to make? Can the PadFone S still be considered a premium flagship device and a worthy sequel to the PadFone Infinity?
Picking up the PadFone S, it is obvious that it is significantly thicker than other flagship models - at a chunky 10mm, it is actually thicker than its predecessor, the PadFone Infinity (8.9mm).
PadFones have never been thin, due to the internal hardware required to make the tablet connection work.
Despite its bulk, the phone is not too heavy at 150g, which is slightly over average.
Like the PadFone Infinity, the PadFone S sports an aluminium frame with chamfered edges. However, the rear panel gets a downgrade design-wise, as it is now a piece of removable polycarbonate plastic.
It feels quite cheap and is not up to the quality of previous PadFones that sport aluminium backs.
Like other PadFones, the PadFone S can be docked into an optional docking station - which costs an additional $199 - to transform it into a 9-inch tablet.
This is, unfortunately, nearly half the price of the phone itself.
If the PadFone S is considered thick, then its tablet form could be considered monstrous. While the tablet itself is only 11.6mm thick, which is not too bad, the docking section is much thicker and sticks out the rear.
This results in a tablet that is effectively thicker than most ultrabooks and even some multimedia notebooks.
The combined weight of the docked PadFone S is not flattering either. The dock weighs 514g - more than three times the PadFone S. Combined, the two weigh 664g, which is too heavy for everyday tablet use.
The phone's full high-definition display boasts great clarity, if not particularly amazing colour reproduction or contrast.
The PadFone S is equipped with a 5-inch screen that has a resolution of 1920 x 1080 pixels. This gives it a pixel density of 441ppi, which yields very crisp and sharp images.
The tablet dock has a 9-inch screen with 1920 x 1200 pixel resolution. This falls short of other flagship tablets, such as the Apple iPad Air 2 and Galaxy Tab S series. Yielding a pixel density of 251ppi, the display is rather unimpressive.
Even with the slightly improved processor, there is not much here for PadFone Infinity users to get excited about, and it is hard to advocate the PadFone S as a true successor to the Infinity. But it still offers flagship-level performance.
The PadFone S runs on a Qualcomm Snapdragon 801 quad-core 2.3GHz processor.
The phone fares worse than some flagship phones - like the Samsung Galaxy S5 - in a test that evaluates a device's various components, including its central processing unit, memory and 3D graphics functions.
But it still scored within an acceptable range, although it did not do as well as the PadFone Infinity.
The PadFone S also equals or surpasses other flagship devices like the Galaxy S5 and the PadFone Infinity in the 3DMark Ice Storm Unlimited test that involves graphics.
Camera performance is on a par with previous PadFone devices. The PadFone S comes with a 13MP rear camera and a 2MP front-facing camera. Despite its low price, the PadFone S' camera performs rather well under normal lighting conditions.
The rear camera also comes with Pixelmaster technology, which serves to illuminate photos better when taking photos in dim lighting. It is also able to snap night photos fairly well, though the noise captured may be significant as well.
The PadFone S runs on Android KitKat (4.4.2) with Asus' ZenUI overlay.
With the PadFone S and ZenUI, Asus has continued the tradition of being able to smartly transition between phone and tablet forms.
In both modes, Asus has made the ZenUI experience as close to the stock Android experience as possible, with the notable exception of the tablet having only a single app drawer, instead of two for stock Android KitKat.
Based on our standard battery test for mobile phones, the PadFone S managed to run close to seven hours, which is somewhat low when compared with other flagship phones.
When docked, the overall battery performance was good, but not enough to rank as well as some of the leading devices. It managed to last for only 81/2 hours. Clearly, it loses out to the Samsung Galaxy Tab S 10.5 and other devices.
At just $449, PadFone S is the most affordable PadFone Asus has ever made. The Infinity's $898 launch price was a lot to ask for, especially for such an eccentric design, but $449 might just be low enough for anyone intrigued by its hybrid proposition to give it a go.
But the PadFone S is probably the worst PadFone advancement for Asus, with cutbacks in both design and build quality.
Still, there is a lot to like about the PadFone S. Even if you ignore its docking tablet capabilities, you are getting a lot of value for the phone.
It boasts flagship-level performance and the aluminium frame is attractive, if not particularly exciting to behold.
If you intend to purchase both the phone and tablet, get them at a bundle price of $598 at the online store, which will save you nearly $50.
All things considered, the PadFone S probably works better as a phone rather than a two-in-one device.
It delivers fantastic performance, along with a decent camera and great display. At this price level, we are willing to overlook its bulkiness and uninspired design.
Visit Hardware Zone for more stories.