The traditional 3 angle "grinder" has been obsolete for years, being replaced by profiled carbide cutters a-la Serdi, Newen, Rottler, to name a few. But I wouldn't be so quick to say cutters are now obsolete due to the advent of a single point profile cutting machine. The quality of the valve job will ultimately be determined by the skill of the operator.
I shiver to think of the cost of one of these SP machines and the attending cost of the valve job that will surely follow to pay for them.