Unfortunately, RP doesn't have any Tru Pro (Tier One) string data, nor do they have Wasabi-X (they have plenty of other Toroline poly's, but not Was-X, for whatever reason). Short of that, here's both gauges of Sync and both gauges of Swift White (click to enlarge):
Those numbers tend to corroborate with my experience, having playing Sync and Swift White in both gauges now. Sync is a little bit more slick, so snapback-based-spin is a bit better; Swift is a hair softer, more comfortable, pockets deeper and dwells longer per unit tension, also a bit more physically stable, and ever-so-slightly more powerful.