Sorry I just went down the thread and you are talking about Pro Tools, but nonetheless they may have some similar ADAT priority scheme to RME.
I used to obsess about unnecessary AD/DA conversions, until I got some good analog gear. You will find that the best mastering labs actually do an extra AD/DA conversion in order get a better less digital sound.
Run those old synths with cheap converters through certain high end analog gear and you will be blown away. If you like metal just the Great River pre-amp is a good start and complements Eventide's gear well.
IMHO avoid UA gear. Their plug-ins sound better than their hardware. I don't think that their plug-ins work with Pro-Tools and anyway don't hardly overlap with Eventide's.
