We just did our first EZ EFI install here a few weeks back on a 410ci -351W stroker with a DC&O manifold- waiting on finishing up some suspension work on it before putting through major driving but I was amazed how quickly it picked up on self tuning in the limited driving I did. Within about 50 miles it had worked out low to mid throttle accels on 1-4th up to about 65-70 mph and WOT sounded dead crisp the two times I floored it from a stop just to see how it behaved. On first startup it cleaned up the idle within about 2-3 min and starts up every single time with a turn of the key. I'm pretty impressed so far.
We've been using the XFI for the last couple years on a lot of cars but for street driven N/A stuff its overkill. I'm really excited about the EZ EFI for my street driver clients.