Last season the Championship was a slog. The fixtures were bunched up even without Covid outbreaks and the empty stands made it tougher. In many respects, the Millers were good enough for the division, but their finishing was not clinical enough to make that count for anything.
Back in League One with an XI made up entirely from players in last season's squad, they went 2-0 up during a fairly evenly-contested first half precisely because they had a ruthless edge, and went on to finish the game much the stronger side.
Freddie Ladapo and Ben WIles took first-half chances and when Plymouth Argyle had opportunities either side of the break, they did not. From there, Rotherham's finishing returned to its more charitable norm but the job had been done.
The game was played at a good tempo thanks in no small part to the support coming from stands bereft of fans in a competitive game since February 29, 2020. They quickly made a difference.
Plymouth brought a travelling contingent of 1,102 who were in their seats early as Rotherham's struggled with technical problems at the turnstiles or caught up with old faces in the concourse. But by the time the game kicked off they made their presence felt.
Argyle's decided to bait their former striker Ladapo at a 10th-minute corner taken in front of them.
Ladapo has missed that sort of motivation and when the ball came loose at a goalmouth scramble, he pounced to tap it in from a couple of yards out before cupping his ear to the away supporters.
There was a positivity and a hunger about both sides, Paul Warne fielding two genuine wingers, Chiedozie Ogbene and Mickel Miller on the outer edges of his 3-1-4-2 and holding midfielder Dan Barlaser rattling into tackles. It was a good demonstration to substitutes Josh Chapman, Ollie Rathbone, Shane Ferguson, Hakeem Odoffin and Rarmani Edmonds-Green of the Rotherham way. Rathbone, Ferguson and Odoffin made it on for debuts in the second half.
Not that the Pilgrims were timid - they hardly could be with their passionate following to represent.
Jordan Houghton sent a volley just over in the third minute, and it took Viktor Johansson glove to make sure the next shot he got hold of from distance did not find hit net on the half-hour.
In between time, Dan Scarr headed a deep Conor Grant free-kick over.
It was no stroll in the park for a Rotherham side who looked to feed Ogbene whenever they could. He had a shot blocked when he cut inside, but generally Rotherham looked to cross as is their way.
With a but more composure, Wiles might have opened the scoring by converting the pull-back from Barlaser's corner but it would prove a god dry run for the goal he did score.
With seven minutes to half-time it was Michael Smith who pulled the ball back, again from the right, and this time the finish into the top corner was exemplary.
By contrast when the first half finished with a goalmouth scramble from a Plymouth corner, Rotherham bundled it clear and when Ryan Hardie, a late change to the away team, had a chance 45 seconds after the break with Richard Wood standing off him, his chip missed the target.
Scarr was picked out by a deep 49th-minute free-kick but when he volleyed it across the six-yard box, there was no one there to get a touch. It would be the difference between the sides.
Getting a third would be beyond Rotherham, Mickel Miller overhitting a pass to Ladapo, who produced an easily-saved shot when he muscled through. Miller was also denied after a Wiles pass and Ogbene could not keep his effort down when Smith picked him out. Jamie Lindsay did well to twist his neck around a header, but could not quite steer it on target.
Wes Harding felt the love of the crowd after some excellent defending at the byline in the 78th minute and it lifted his performance, producing a rampaging run a few minutes later and generally lifting his level from very good to man-of-the-match.
Rotherham United: Johansson; Harding, Wood, Ihiekwe; Ogbene, Lindsay, Barlaser (Rathbone 59), Wiles (Odoffin 76), Miller (Ferguson 83); Smith, Ladapo.
Unused substitutes: Chapman, Edmonds-Green, Sadlier, Kayode.
Plymouth Argyle: Cooper; Wilson, Scarr, Gillesphey; Edwards, Camara, Houghton, Mayor (Broom 63), Grant (Randell 76); Hardie, Jephcott (Shirley 76).
Unused substitutes: Burton, Galloway, Law.
Referee: S Stocksbridge (Tyne and Wear).