I'd say give it a try on your own first.
Upgrading should just mean saving a backup of your files (just in case... better safe than sorry)
Then overwriting the old files with the new files from the update .zip file.
If you run into issues, then you can always go back to your previous version you have saved.
You can of course pay for a premium support ticket and have one of us call you and walk you through it, but give it a try on your own first and you'll likely save yourself the ticket price.
For the most part if your site is up and running and you are happy with performance and not running into any issues that appear to be bugs, then you don't have any real reason to update. The only significant feature addition is moving the credit card information to the confirm page so that users can see their total with tax and shipping before entering their credit card, so if that is compelling enough for you then that might be a reason to upgrade as well.