The less encouraging news for New Zealand is that he's happy with progress, likes the look of the pitches so far, and is confident he'll quicken up with more overs behind him.
"The way the wickets have played, there's been a bit of pace and bounce in them. If the tests are anything like the same we could cause quite a stir.
"I think I get better and quicker the more overs I bowl.
"So far [limited-overs captain] AB de Villiers has used me in short spells. The longest has been three overs, and it's quite difficult to get the pace right up there if you're going to bowl short spells."
Steyn is expecting more work when test skipper Graeme Smith takes over next week.
"I know Graeme will give me lengthy opportunities to bowl, maybe six or seven overs and maybe then I can cause bigger trouble for batters with more pace."
Steyn is on his first tour of New Zealand. The indications he received from others who had toured here before to expect low, slow strips have so far proved wide of the mark.
"Surprisingly they've been very good, and good for batting, too," he said. "Every time the New Zealanders have been in, they've looked like being in. That big 100-run partnership between Brendon McCullum and Martin Guptill [in Napier last Wednesday], it took some bowling to get a wicket."
That sounded as if Steyn was lending some weight to New Zealand's contention that they have played patches of good cricket, just not enough against mentally strong opponents.
Back to speed. Craig Cumming can attest to his pace. The former New Zealand opener was felled by a short ball at Centurion five years ago.
It happens that was around the time Steyn was talking about as his peak in terms of straight speed. But there's more to his game than that.
Morne Morkel is the bounce man; Vernon Philander, the anticipated third member of the test seam bowling triumvirate, is not as slippery but is accurate and nips the ball off the pitch.
But Steyn is the chairman of this particular board, the Rolls-Royce in South Africa's garage.
Born in Phalaborwa, northeast of Pretoria and near the famed Kruger National Park, Steyn has the gunslinger's sharp-eyed glint, a man who knows his business and relishes doing it well.
His smooth acceleration and run through the crease could be a model action for aspiring young fast bowlers. His outswing is pronounced and late, so he is a constant threat.
His first ball in New Zealand, in the opening ODI at Wellington last weekend, beat Rob Nicol comprehensively.
Steyn also revealed a quirky way of describing moments. The next delivery took the edge of Nicol's bat and flew over second slip. His feet hadn't moved, perhaps anticipating a short ball or something quicker.
As Steyn put it, Nicol's feet were "still in the toilet" when the ball reached him.
Steyn's test numbers are eye-catching, but they're even better against New Zealand.
Since his test debut against England eight years ago, Steyn has rattled up 263 wickets in 51 tests, at an average of 23.07.
Seventeen times he's taken five wickets in an innings; four times 10 in a match. Two of those occasions were against New Zealand in 2007, when he ripped out 20 wickets in two tests at a barely believable 9.2 runs apiece.
Overall, five tests have brought him 36 wickets at 16.66. So it's fair to say he's enjoyed himself against the New Zealanders.
And preparations have gone well for this tilt at New Zealand, coming off a break since the end of Sri Lanka's South African tour. He maintains he doesn't obsess about taking wickets.
"I just haven't found the edge. I've gone past the bat countless times in the last two games.
"I've sat back, looked at my performances, and said, 'Where can I make it better?'
... "I'm quite happy with what's happening. "
If Morne is picking up five wickets, and 'Lotsy' [Lonwabo Tsotsobe] is picking up wickets I'm not going to moan.
"But if I keep doing this I knowI'll get a performance that goes my way." On past form, bank on it.
