Not true at all.
First of all, premium members cannot change the appearance of their usernames.
Secondly, the option for Improved and Modified members to change their user title only allows them to change the content of the title text, not any html markups or effects such as were available in the old EFD store (e.g. bold, shadow, font, colors, etc.).
I would love to implement the new and full-featured EFD store as soon as possible. However, forum and server security is more important, and the only available third-party add-ons have serious security holes, unfortunately.
For this reason, I am waiting for the developers who made the current EFD credits forum add-on to complete their forum store expansion. These developers are very talented, and all addons they release are very secure (though unfortunately that process requires more time to develop and test).