I've been running Z12, Z7 and Z3 for a couple of weeks on relatively small accounts and so far Z7 has been the worst performer. It made a couple of moderately bad trades ($10), won back its losses with a couple of okay trades (gained ~$30) and then crashed spectacularly (lost $100) last night thanks to the USD gaining strength.
Z12 has made pretty consistent profits, up to $240 profit in 14 days.
Z3 lost a bunch ($130) on something I forgot and now it's making most of it back with a nice investment in gold.
Overall though, between the three systems, I'm back pretty much where I started.