It took me a while to do those tests .
They were done with the default Standard Battery (2600mAh) from 100% (or almost) to 5% when windows decides to hibernate himself.
Wireless was OFF.
Video playing was done with MediaPlayerClassic.
MP3 playing was done with Window Media Player.

With the Power Profile : Power Management OFF

Running 3Dmark 2003 demo with sound in loop i got around 1h24 of battery life.

Running a Video file encoded in XviD 1496kbps (1024×576 29.970fps) with MP3 stereo sound 48kHz 96 kbps in Fullscreen with sound to the max.

• with the file on Hard Disk : 1h37.
• with the file on Memory Stick : 2h03.

With the Power Profile : VAIO Super Stamina Settings

Running a Video file encoded in XviD 1496kbps (1024×576 29.970fps) with MP3 stereo sound 48kHz 96 kbps in Fullscreen with sound to the max.
• with the file on Hard Disk (using headphone): 2h10.
• with the file on Memory Stick : 2h18.

Running MP3 files with Screen Off

• with the files on Hard Disk (using headphone): 3h20.

So that’s it for my tests on the autonomy of my VAIO UX90S. You can now have a pretty view on how long the UX might last for your needs.

Remarks

When the battery is begining to run out, the power LED flash.

When using the Headphone with the UX with the carrying stand on the table, the headphone’s jack is getting in the way. So you have to either rotate the screen in windows by 180° or you have a BlueTooth Headset (by the way SONY has one listed, the VGP-BRM1.), I recommend doing the rotation since the viewing angle is better, but you can do both