Today Street Fighter X Tekken has received a patch, which resolves a few complaints. The issues resolved include the online sound sync and the ability to change gems when selecting a character. While these sound like great fixes, it appears that many users are noticing increased lag during online play.
The increased lag appears to be a trade off of the new netcode, which caused the original sound delay. There is no word on if they can resolve both issues, but this will be ideally ironed out before the Vita version is released.