Review: Sony Ericsson W580i
Screen
As long as you select a light colored theme, it is easy to see and use the W580i under all light conditions. However, if you switch to one of the included dark themes, it is nearly impossible to use the phone in sunlight, even with the brightness turned up to 100%. The QVGA is sharp and has accurate color reproduction. When you can read it, it is very pleasant to use.
Signal
Though signal strength is often Sony Ericsson's weakness, the W580i performs better than past models. It passed the vault test with flying colors, making calls and getting online with no problems. However, weak signal affects call quality, although the W580i holds on to these calls with no problem, sound is muffled and crackly.
Sound
The W580i isn't just a Walkman phone, it's practically a portable stereo, the speaker is so loud. When the volume is set to 3 out of 8, the ring is loud enough to embarrass you in a fairly quiet room. At 4 out of 8 the phone starts to display a warning that loud volumes can damage hearing and Sony Ericsson means it. At 4 out of 8 the ringer is loud enough to overcome everything but a Dethklok concert.
Phone calls are equally loud and clear. The only time I found myself turning the volume up was when I was in weak reception areas. A weak signal doesn't just affect sound quality, but also volume.
Battery
With the screen set at maximum brightness (the default), the battery lasts just over 2 days. I tried to find some combination of power saving steps (turning the screen down, turning off Bluetooth, etc.) that would yield 3 days of battery life, but not using the phone was all i could do. Pack your charger if you're leaving for the weekend.