your question will probably get moved to a LW forum, but the quick answer is: no hidden difference. It's like they say on the LW home site. Look for "About Limewire" in the menus to see the version (on Mac at least).

The real difference is that you are supporting the development of an opensource project--every advance the LW team makes to the code must be freely shared with anyone who asks for the code.

And that is what this forum is about, so maybe your question does fit here. Welcome to gnutella--glad you're a supporter.