I must admit, I'm nerdy enough that I kinda like the idea, if it works. Not so much for what they are hyping it for (sharing with friends), but just to measure my own progression. I've never actually tried Alpine Replay, but I use Google Tracks occasionally to check my top speed. Again, not to compare with friends, but to track my progress.
Of course, Trace will probably be ridiculously expensive and that'll completely kill my interest.