Xperia Arc eh? I have one myself. If you have any questions, feel free to ask me.
Pros:
- Extremely thin and lightweight. Very, very comfortable to hold. The device itself is beautiful.
- Fantastic 8MP camera, with up to 720p HD video recording. Critically acclaimed by many to be the best camera to appear on an Android device.
- Runs Android 2.3 Gingerbread. Latest update adds "Facebook integration" to the OS, if you're into that.
- Beautiful screen for video playback.
- Smooth experience overall. Hardly any slowdown on phone.
Cons:
- Average viewing angles.
- Single core processor may appear to be slow when faced against dual-core competition. RAM is on the low side.
- Very limited internal memory storage.
- No front-facing camera for self-portraits and video chat.
Other Issues:
- Default launcher may lag at times. I switched to Launcher Pro and never had a problem since.
- Iffy placement of the camera button, and the camera itself. Being close to the edges may cause some fingers to appear on video.
- Facebook and other programs running in the background tend to deplete the battery life
very quickly. I just kill of the Facebook application when I'm not using it.