Windows NT - the OS to run on comparable computers - was cutting edge, and still is in many ways. Don't be fooled by the similarly named products made for 100x less powerful computers.
What I think they were saying was that NT and Unix workstations were peers (running on "comparable computers"), and that NT shouldn't be conflated with 9x ("similarly named products"), which had to run well on much more modest ("100x less powerful") hardware than the aforementioned.
NT and intel didn't catch up SGI/Mips and Dec/Alpha until the Pentium III, and in the case of the Alpha, even the 800MHZ one was subpar against the Alpha.