The important thing for a good green is that it's reasonably true. Pace is secondary, is it not part of the skill to adapt your pace of putt day to day?
But a putt that bobbles, leaps or jumps due to a dodgy green takes all the skill of judging pace and line out of the equation. You need to know and be sure that the putt is going to go where you intend it.
I agree with comment about excess pace on sloping greens. Played the PGA National last year and one hole has a severe back to front slope. Unless you were directly below the hole there was little chance of holing a putt as the speed of the green made it virtually impossible. I putted off the green twice from 4feet missing the cup by a whisker each time. At my standard I don't need that.