Thanks for the videos. I also found an audio clip from "deathmonkey" on harmony-central
Six:X Audio Samples.
I had been waiting to get sense of what this thing would sound like before pulling the trigger on a Mark IV. Admittedly, I knew they'd be very dissimilar. I think I'll be going for the Mark as, while the Sig:X sounds like it might be pretty good, it doesn't sound like it would deliver the smoothness I like.