Lets have a serious discussion of what you deem is the ideal valve angle. A brief search on the net leaves no satisfying conclusive answer as to which angle is the magic number.
While i personally have no magic number offhand, i feel that a tighter/smaller angle is more optimised for higher flow rates with lesser turbulence. Of course if the valve angle is aggressive and the the engine manifold orientation retards air and gasoline flow, then it cancels out the effect of having an aggressive port angle.