The motto "When Choice Matters" represents a myopic view of VL's place among Linux distros. It draws a comparison to a couple other distros, our old nemesis Zenwalk and maybe Absolute. This distinction of "choice" simply doesn't apply to Wolvix, NimbleX, GoblinX, and many of the newer distros. The motto "Discover the Difference" issues a broader invitation and challenge to try VL. It invites a comparison to any and all distros, not just the SW-derivative frontrunner ZW.
Choice is an important criterion in the evaluation of a distro. But do we really want to hang our hat on this one superlative of VL? What about speed, performance, and stability? What about support community?
Then there is the grammatical sense. When exactly does choice matter? I'm guessing it matters all the time, so this qualifier is perhaps rhetorical. "Discover the Difference" is in the imperative mode, and unambiguously urges action.
I'm in favor of reinstating "Discover the Difference" as the VL motto, with no dots. (It's a complete sentence, not just a fragment, so it doesn't need dots.)