Alcatel has unleashed a slew of new phones onto the market here on the first day of Mobile World Congress, but the most interesting two lie at diametric opposite positions on the smartphone spectrum. We first got to spend a few minutes with the new One Touch Idol X, an ultra-high-end phone with a 5-inch, 1080p display. On one hand, these displays are increasingly commoditized as every company on the planet incorporates them, but on the other the Idol X is a very impressive sight to behold. It's only 7.1mm thick, the same as the original Droid RAZR; the bezel around its display is also just 2.4mm. Together, they make the Idol X feel much smaller than a phone with such a large display should. The phone's other specs are impressive, though they vary around the world: it will have either an 8- or 13-megapixel camera, depending on the market, and either one or two SIM cards slots. The phone runs Android 4.2.1, and in our time with it felt snappy and responsive — Alcatel has skinned the operating system, but it didn't seem to be much more than just a re-designing of the system's icons. The Idol X is coming out in the second half of this year, and appears at first blush to be a solid option.

On the complete other end of the market lies the Alcatel One Touch Fire, an ultra-low-end phone running Mozilla's new Firefox OS. This device is small – its 3.5-inch screen feels positively miniature now – but it's thick, clearly underpowered, and only capable of executing the most basic tasks. But it's a completely different device, with a completely different intended customer: Alcatel says it will be sold almost exclusively in developing markets when the Fire goes on sale this summer.