The Good: Sleek unibody design. Good battery life. Outstanding AMOLED display. The Bad: No user replaceable battery. Non-expandable memory. Not significantly different to Lumia 800. Not upgradeable to Windows Phone 8. The Bottom Line: The Lumia 900 is a fish out of water in Australia in 2012. It's not that different to its forerunner, the Lumia 800, and its not upgradeable to Windows Phone 8. Those interested in Microsoft's OS should wait for newer models later in the year. The Lumia 900 hit US stores in January, preceded by accolades and fanfare. It would take the top spot as the 4G flagship for telco Sprint and it seemed to have a bright future. As it strolls into Optus stores in Australia, sans 4G and with the knowledge that it won't be upgraded to Windows Phone 8, the story is quite different.\r\n\r\nDesign\r\n\r\nFrom a distance, you might feel as though you've seen the 900 before. It shares the same unibody design as the Lumia 800 and Nokia N9 before it, with the same flats and curves, ports on the top and speaker across the base. In the hand, the 900 feels quite different. Our review unit is a glossy white, not unlike the a few weeks back, and it has the same smooth, porcelain-like feel that the GS3 has too, not the grippier soft-touch plastic feel of the Lumia 800.\r\n\r\nIt's screen is bigger than the 800, up to a generous 4.3-inches diagonally, and with the same excellent AMOLED panel below the glass. Colours are rich, if a tad oversaturated, and the blacks are excellent. The touchscreen is also worthy of praise; matched with the slick Microsoft OS, the input is flawlessly reactive.\r\n\r\nThe Lumia 900 is sealed, so you won't be able to access the battery to replace it and Windows Phone 7.5 doesn't allow for expandable memory via a micro-SD card, so the SIM card slot and headphone socket are the only external breaks in the heandset's smooth, seamless exterior.\r\n\r\nFeatures and performance\r\n\r\nReleasing the Lumia 900 now will likely go down as one of the most baffling smartphone releases in Australia this year. In America, the Lumia 900 wasn't just a bigger Lumia 800, it was a Sprint exclusive model and one of the first Windows Phone products to come with 4G network speeds. It had a significant point of difference.\r\n\r\nLocally, the Lumia 900 is just a bigger and, currently, more expensive version of the Lumia 800. Optus will range both models simultaneously, with the 800 available for AU$5 less each month, at the time of writing this review (though this is likely to change). Without 4G speeds, the screen is one of a few differences between these two phones, and we think this leaves the 900 at a disadvantage. Both phones have the same processor and GPU, the same 512MB RAM and the same 16GB storage. Both have an 8-megapixel camera with LED flash, the same networking features and run on the same version of Windows Phone 7.5.\r\n\r\nNokia does give the 900 a larger 1850mAh battery though, and it's one of this phone's stronger suits. In a continuous video playback test, the Lumia 900 managed to play the same 720p video file for just over six hours and fifteen minutes. Given that the best result we've seen in this test, so far this year, is seven hours (for the GS3), the Lumia sits at the better end of power efficiency. This translated well in everyday use, with the 900 nearing two business days between charges.