Equal first: I came to this phone, like the Virgin to the child! I was traveling on the road and had to admit that has Z8 given up the ghost of my Motorola battery. Wanted to quickly buy a new, but no local electronics shop he was still available. But since I needed a phone and now did not want to spend lots of money without any preparation I reached then the SE W350i to. Was supposed to be only a transitional mobile ;-) Today it is my "master phone". Buying an MP3 player I have done by a 4GB card for 350i. As for the menu navigation, so I can only say: Absolutely intuitively. The keyboard is very good to use and even for my big fingers! The Menu button I can not "fingernail" operate as described here in another review. The battery lasts at me for a long time, just as an example: fully charged Sunday night. Mo 6 hours long listened to music business trip. The rest of the week added up approx 15 hrs Msuik heard and then the phone still about 1.5 hours. Some written SMS and the mobile phone is always on. In this usage holds a battery charge with me about 1 week. Can not complain. Oh, Bluetooth was also switched to hands-free for Verbidung in the car. Regarding mentioned here "misconstruction" the battery cover and the flap, so I can not share this opinion. Despite multiple opening the battery cover to the memory card to take out the loaded he still holds by. The flap is also in a good condition. The only thing that is true is that the dubbing time required by the PC to the device via the USB port for a long time, and it automatically converts my ogg files to mp3. And that just takes in 4GB something. Converts putting them on the PC directly to MP3 and play the data on the card with an adapter directly to the PC, it is faster. Synchronization works with Windows products properly (Calendar and Mail if you use Outlook no), otherwise just with Outlook. The included software is easy to handle and also a firmware update is thus without any major problems. My first was a SE K750i with whom I was very disappointed at that time. But I must say, because a lot has happened and I can only recommend this brand! Does anyone have any questions, just ask :-)
Addendum: As regards the duration of the batteries: The natürlcih is also dependent on how the MP3 Tittel encoded (bit rate) and how loud they are playing!