As in previous practice, mobile device makers slash down on retail price of old models to keep the product moving, which exactly is the case of the Galaxy S3 as release date of the Galaxy S4 nears.

It has been a roller-coaster ride for the former Samsung flagship in the past few months as the handset saw its global price marks fluctuate from $99 to as low as a penny. The deliberate ploy was, of course, intended to keep the sales numbers moving.

In many cases, the approach proved effective, convincing many buyers to snap up the generation-old GS3, their interest buoyed further by Samsung's pronouncement that most of the new GS4 features will be ported to other high-end Galaxy devices, the GS3 including.

Yet for forward-looking Android handset buyers, the better buy between the two devices is the GS4 and the reasons are detailed below.

Longer lifespan

Serious buyers pay serious money for their gadget of choice. And they intend to juice every bit of penny on that purchase. As a long-term 'investment', the GS4 poses the better prospect for users looking into its capabilities right out of the box.

The new smartphone is expected to keep up at least over the next two product cycles until users feel the itch for an upgrade. But before that moving-on phase, the GS4's hardware and software muscles should suffice for both the average and advance users. It is safe to assume that even if chip makers will successfully break the 8-core limit in the next two years, the GS4's mix of Snapdragon and Exynos CPUs will be able to contend, and effectively.

Plus, with the top-notch components inside its guts, it is more likely that the Samsung flagship can accommodate all the Android and TouchWiz updates to rollout over the next 36 months.

More compact and durable

The GS4 represents Samsung's shrinking device footprints. That means starting with the new handset, the South Korean tech giant is opting for optimal device design that focuses on less heft but more functions.

Note that the GS4 sports a bigger screen, at 5-inch, compared to the GS3's 4.7-inch but the former is thinner, lighter and stronger. In short, solid and creative engineering is behind the overall GS4 build.

More power-packed features

It is true that the GS3 is not too far behind from its newer sibling. But over the long haul, the old flagship will gain age and like old machines, the handset will eventually admit its limitations.

It is doubtful if the GS3 will deliver the full capabilities of the new features that Samsung showed off when the GS4 was unpacked on March 14. It could be that eye-tracking, motion scroll, Air View and other Smart features will make their way to the older phone but the rendering will never be same as experienced via the newer phone.

Better accessory flavours and support

This could come in colourful protective cases and other attractive mobile device blings. But the one that really mattered for Galaxy fans is the wireless charging capabilities that the Nokia Lumia 920 and the Nexus 4 proudly displayed last year.

Technically, or with some tweaks, the GS3 can be powered up using a Qi standard wireless charging kit. Samsung picked up from that and made sure that the GS4 will support the emerging technology. Plus some bonuses: a higher battery rating and a removable back cover - two features that ensure GS4 users can enjoy full smartphone functions without dealing with a low-batt scenario.

Superb screen technology

This, by far, is the top GS4 menu feature. Samsung has let out its first take on the Full HD Super AMOLED display technology via the Galaxy S4, which is a major climb on the already impressive earlier AMOLED editions.

With the new screen tech, the GS4 is easily the best 1080p handset out there, its HD rendering besting iPhone 5's Retina while affording GS4 users the luxury of carrying on their pockets a portable HDTV device that is both immersive and jaw-dropping.