I wish this spoke vs cast rim issue was just as simple as picking colours.
I was going to do some physics calculations at higher accuracy (not involving the effects of tire and flexing of it at higher speeds along with the effects of gravity due to vertical alignment), but I decided for later if time permits.
Here's what I think: Assuming total weight to be the same for either rim, the geometry of weight distribution are quite different. Spoke rims will weight higher at the ends, because of total weight minus the small weight of sum of spokes. While the Cast rim will have weight distributed across the wheel due to weight of cast spokes. Hence, I suspect the centripetal acceleration to be different, while the centrifugal force may remain somewhat the same (it could also change). Due to increased centripetal acceleration for a spoke rim at a given constant speed, the effects of turning on a curve would be pronounced as we increase the angle of lean.
This effect translates to a feel and handling of a bike on a paved curve. Scientifically, it would be there, however, once you start riding your own bike, you get accustomed to its handling, and you make adjustments to it without even knowing. This is what I call your "style" of riding. We ride bikes that we own, unlike journo's who tests them against another.
So, IMHO, I think get the wheel you want, spoke is great because it has tendency to flex if you were to go off-roading or unexpectedly go over big bumps, it will be far more forgiving. It also means about $500 more as an option!