Hi Rob,
There are many new features included with version 5 of eCart. Some of these new features include a color management feature being added to the Display Manager, better handling of image type columns in the Display Manager, a major overhaul to the Checkout Wizard interface to simplify work flow, and added three extra default designs... just to name a few. For a complete list of the new features available in version 5, please click on the following link and then choose the "Features" tab:
?WAAID=896
Also, because you already own version 4, you are being offered a significant discount for version 5 in your Upgrade Center. You can click on the following link to access your Upgrade Center:
upgradecenter.php?WAAID=896
If you have any other pre sales inquiries, please contact me at sales@webassist.com.