* Software can be taken with all its personalised settings to any computer running a compatible version of Microsoft Windows, with no need to install the software if not already there, or to use different settings and options, and no need for administrator access privileges.
* Software is available from the U3 site, including amongst others Trillian, OpenOffice.org, Filezilla (FTP app), Firefox (Internet Browser), Sudoku (Game), Skype (Phone calls from your computer).
* Programs are run from the Launchpad, functionally similar to the Windows Start menu familiar to most users of Windows XP.
* New software can be downloaded to a U3 flash drive without the requirement for administrative privileges on the host computer.
* Many U3 drives come with virus protection software which gives protection against being infected by or spreading computer viruses.
* Some popular free portable application programs available at PortableApps.com for non-U3 flash drives have been adapted for use with U3 drives. They are available at the web sites of U3 and PortableApps.com.
Several criticisms have been made of the U3 platform. These criticisms are:
* Closed Platform - The U3 platform is closed and only open to vendors that U3 chooses to admit.
* Lack of Reliability - On some systems, U3 attempting to start up will cause the computer to freeze.
* Stress on drives - USB flash drive technology was not originally designed to handle the large number of write operations associated with running software
* Not Uninstallable - The U3 Launchpad cannot easily be uninstalled by an end-user. However, U3 has responded to this criticism as they have recently made available an uninstall feature on their website. This is thanks to Best Buy's Geek Squad who in early 2006 raised the issue of not being able to uninstall with U3 and got them to write a uninstaller for first the Geek Squad branded drives and then all the U3 drives. Unfortunately, the uninstaller doesn't work in all cases. As of November 2006, U3 drives now come with an uninstaller on the USB drive itself.
* Leaves Traces on Host PC - The U3 platform sometimes leaves behind files on a user's PC. This mainly occurs when the drive is improperly removed.
* Data Security - Most U3 drives on the market feature a security lock within the U3 Launchpad. This loads the CD partition first and requires a password to be entered, otherwise the data partition will not load. The drive is supposed to seal itself after a certain number of invalid password entries, requiring a reformat. Additionally, since the data partition is not encrypted, an end-user's data may not actually be secure as the U3 CD-ROM partition can be easily be used to store any program.
* Latest versions of Nero's InCD tend to be incompatible with U3. Since u3 mimics a CD drive, InCD tries to operate on it and freezes the system. The only solution is to uninstall InCD or get an older version of InCD. InCD is used for adding drag and drop functionality to CD-RWs and DVD-RWs.1
* Compatibility - Some non-Windows users and users of older versions of Windows (pre-Windows 2000) experience problems using U3 drives, apparently because the emulation of a "vanilla" USB drive is imperfect.
* Viruses - Some users may be uncomfortable with the automatic installation of the Launchpad software that arrives on each U3 drive, since this would make a terrific virus vector.
* Problems - Where a user has insufficient privileges he may run into problems getting the launcher to work. In such a case the launcher might actually prove a hinderance to using the device