A reason for using narrow beam lights is so that you will get areas directly below which are better illuminated - spot light.

With the higher output generation CR/ LR 6 type lights, it is possible to have lights that have more output and yet are diffuse enough for general illumination without shadow regions.

The Cree website has charts showing the illumination possible with height and angle.

A downside to having can lights in a very high ceiling is that it will be difficult to install and service them.
An viable alternative to Can lights is cove lighting where the light is reflected off the ceilings and produces a very elegant environment.