All editions share the same set of features but differ in the device you install the application on.
If you like the idea of having software installed on a removable drive, so you can always plug the drive into any Windows machine and start using it with no delay, you should then install the Allway Sync 'n' Go edition on your flash drive or external hard drive. This is also a great choice when you mostly need to synchronize data on your USB drive with one or multiple PCs, especially when you are not allowed to install software onto some of those PCs.
If the USB drive you plan to install the program on bears the Sandisk "U3" logo then you should use the Allway Sync 'n' Go U3 edition instead.
If you usually work on a single computer and want to synchronize it with a network shared folder or with multiple disks then you should download the conventional Allway Sync edition and install it onto your Windows desktop or laptop. Also install Allway Sync on your PC if you are a novice user of this synchronization software and you are not sure which edition you need.