Thankfully, call quality is as good as should be expected from a company that's been making mobile phones since 1984, and the loudspeaker on the bottom edge of the case is loud and clear in speakerphone mode.
The other change from the N9 is with the processor and the Lumia 800 has a 1.4GHz Qualcomm Snapdragon rather than a (functionally very similar) 1GHz ARM Cortex-A8. We haven't tested the N9, but the score of 89.82 in the WP Bench synthetic benchmark puts the Lumia 800 near the top end of the performance pile the HTC Titan with a 1.5GHz Qualcomm chip scored 98. Internet Explorer's JavaScript performance still seems to be a weak spot compared to that on other smartphone operation systems though, with the Lumia 800 scoring 6,793ms in the SunSpider test (where lower is better) and 32,236 in the BrowserMark test (where higher is better) the iPhone 4S with iOS 5 scored 2,200ms and 87,993, respectively.
As the one-piece case suggests, the Lumia 800's battery is non-removable, but it lasted for a very respectable 45 hours when playing MP3s with the screen and wireless radios turned off. Performance with the processor-pounding WP Bench batter test was less impressive though, and the Lumia 800 managed a mere two and a half hours the similarly specified HTC Radar with its marginally bigger battery ran for six hours.
