I've used full-blown telescope equatorial mounts before, from a medium Vixen Super Polaris to a back-breaking Skywatcher EQ6, so the AstroTrac is feather-light and compact in comparison.
I really, really wanted to get away from the German-equatorial style with lopsided camera positioning, counterweight bars, big battery packs, controller handsets, and cables hanging everywhere. I wanted to recover the sense of mobility, quick set up and convenience that comes with fixed-tripod astrophotography...Several of my happiest memories from the past 25 years are of hiking a short distance at night with a tripod over one shoulder and a camera bag over the other one, to get a better vantage point or darker sky for photographing a comet or a conjunction. At such times, I have experienced the purest expression of freedom and the deepest appreciation of nature.
Anyway, before I burst into tears at the recollection of it all , I'll just say that the AstroTrac is now starting to recreate that vibe for me...with of course the new dimension of superb sky tracking.