Four years ago, Apple removed the 3.5mm headphone jack from the iPhone 7. Despite the initial outrage, you cannot find a headphone jack on a flagship smartphone today.

Perhaps Asus is hoping for the same result because the Taiwanese PC maker has done the same to its ZenBook 14. It is a gutsy move, as even Apple notebooks still retain the headphone jack.

Asus sent reviewers a presentation deck to defend its decision, saying that consumers already have Bluetooth headphones for their smartphones that can also work with the ZenBook.

It explained that the notebook lacks the space for a headphone jack because it already has an HDMI port and a USB Type-A port.

But, to borrow a line from Shakespeare's Hamlet, methinks Asus doth protest too much.

I do not buy the brand's arguments, as there appears to be sufficient room on the ZenBook 14. And I cannot imagine my wireless earbuds being able to last an entire work day on a single charge.

The bundled USB-C-to-3.5mm dongle helps to mitigate this problem, but it is yet another accessory to carry around.

The ZenBook 14 is available in two variants - the UX425 uses 10th-generation Intel processors, while the UM425 is powered by AMD's Ryzen 4000-series chips.

The Intel version has a slightly brighter 300-nit screen compared with 250 nits for the AMD model. And the Intel version has Thunderbolt 3 ports (up to 40Gbps) while the AMD model has USB Type-C ports (up to 20Gbps).

Both types of ports can be used to charge the laptop.

These differences aside, the two variants have an identical chassis with an almost-bezel-less 14-inch Full-HD non-touch display.​

The top display bezel is slightly thicker to accommodate an infrared 3D camera that can be used for facial recognition.

While the maximum screen brightness of the AMD-powered UM425 is only 50 nits lower than the Intel-based UX425, I find the UM425's display duller than the UX425. Both displays do not look as vibrant as other ultrabooks I have tested.

The laptops are very portable at around 1.2kg. On paper, the Intel model is slightly lighter than the AMD version, but the difference is negligible.

The ZenBook's slim aluminium body feels a bit creaky with some flex. The chassis tapers to a thin edge at the front lip, which digs slightly into my arms when they are resting on the palm rest.

Despite the laptop's slim profile, its keyboard has decent key travel. However, typing on it may take some adjustment - especially when locating the Enter key - as the keyboard has an extra column of keys at the right edge for the Home, Page Up/Down and End keys.

Having tried several notebooks with a compact 3:2 aspect ratio recently, I also feel that the ZenBook is wide. This impression is further reinforced by the touchpad, which is wider than usual and clicky with a smooth glass surface.

The touchpad also doubles as a numeric keypad. Tap the calculator icon on its top-right corner to get an illuminated numeric keypad overlay that is handy for data entry.

While there is little to differentiate between the AMD and Intel variants of the ZenBook 14 in design and features, there is quite a significant gap in performance.

The AMD-based UM425 has an eight-core Ryzen 7 4700U chip that handily beats the quad-core Intel i7-1065G7 chip in the UX425 in the PCMark 10 system benchmark.

The UM425 scores 5,150 compared with 4,324 for the UX425. Notably, the UM425 scores 32 per cent higher than the UX425 in the Digital Content Creation segment, which involves video and image rendering.

But the tables are turned in The Straits Times' video-loop battery life test. While the UM425 clocks a good result of seven hours and 25 minutes, the UX425 is much more power-efficient, lasting almost nine hours in the same test.

If you can accept the lack of a headphone jack, the Asus ZenBook 14 offers good performance and excellent battery life in a portable package.

Best of all, you can choose between the AMD model, which also happens to be slightly cheaper, for performance, and the Intel version for battery stamina.