Firewire and USB are both more than fast enough to handle the highest resolution audio currently available. Any additional speed isn't needed. The current high end Firewire and USB DACS sound excellent. If you are ready to make a move do so now. The technology is very mature and faster speeds don't matter. Waiting to buy for the next best generation of data transfer, or speed, or price drop, or whatever will mean you will be waiting forever. While nothing is obsolete in 16 months, everything will be surpassed in that time.
You answered your own question, move now or wait forever.
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You answered your own question, move now or wait forever.
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