I drilled my first Rico1 Friday for a friend who has a fairly low track. The ball was a Lanemasters Deep Impact (symmetrical core) that I plugged. Before I glued the thumb sleeve and finger grips in and added the weight hole, I threw it myself with the raw holes. My track is higher and inverted (PAP 5 3/8 over and 1 3/8 down). For me, the track moved up to about 1/2" away from the thumb and fingers, no longer inverted, very little flare (with my PAP the layout was probably almoxt 5" pin to PAP). Not sure why the inversion changed, but it could be because both the thumb and finger holes were way oversized so I had to grip it to avoid dropping it. The ball was very smooth and read the lane well. Not jumpy at all. It hit hard. When my friend threw it, first without a balance hole - it worked out to be legal without one, his track moved up but was still well away from hitting a hole. Ball reaction was very similar to what I had seen. I did drill the balance hole, 3/4" diameter and almost 3" deep. Did not see a drastic change in ball reaction but the bowtie moved up considerably.
The basics of the layout are: pin at grip center, cg located 45 degrees from the pin toward the negative thumb quadrant, with the balance hole 6 3/4" from the pin on a line from the pin through the cg. BrunsRich developed this layout, so if you want more information send him a PM.