RWBY is cool and all, but...

SWPPHIRE doesn't work as well as RWBY, unfortunately. In RWBY, all vowels (except y, but it's not part of the conventional five vowels, so it's okay) are replaced by W. This isn't done in SWPPHIRE, and can't be done without looking ridiculous. Yes, both have the first vowel replaced with a W, but RWBY has the additional property of having all vowels replaced. Not to mention W is pronounced 'double-U', and the letter replaced is a U. It just justifies a little more the pronunciation of RWBY as ruby. Again, that can't be done with SWPPHIRE.

Therefore, RWBY is better.