I agree with all of what Bill says. My only exception point is the price now demanded by 3Rivers for the Dalaa riser, which is not the space-age aluminum derivative used in the Master Hunter or original series; it is, I believe, an industry-standard 6061 derivative, and even with the anodizing (which is quite nice), is understandably hard to initially justify $500 or $560 for just the riser.
It will, however, be absolutely bulletproof, well made, well thought out, and well engineered. They have an intrinsic balance, inherent accuracy and mass damping effect, and are not stamped/cast like some cheap $100-$150 ILF risers on the market.
They are "custom engineered", and produced on a high-tolerance CNC machine. David does everything on his own as far as machining; I do not know if he ships out for anodizing, but I believe he does.
He had some other economical risers planned, but they have been postponed for the time being.
Take Care,
Marc