Van Persie landed both the PFA and FWA player of the year prizes last term for his outstanding form at Arsenal.
Yet, much as Arsene Wenger views Champions League qualification as an end in itself, the Dutchman remained unfulfilled.
After seven trophyless seasons with the Gunners, the 29-year-old decided it was time to head down another avenue, and much to Roberto Mancini's chagrin, he opted for United ahead of Manchester City.
The move looks to have worked out for all parties.
Van Persie took his tally to 19 with a double at Wigan on Tuesday, ensuring the Red Devils maintained their seven-point advantage over City at the summit of the Barclays Premier League.
However, as a veteran of five championship-winning campaigns, Ferdinand is acutely aware there are greater rewards at stake than just sheer weight of goals.
"Robin is an important player," said Ferdinand.
"The manager saw something in him and made it his mission to buy him this summer.
"At the moment, thankfully, he is doing what he came here to do.
"He is not only scoring goals. He holds the ball up well and brings others into play. He does a fantastic job.
"But we are not at the end of the season yet. No medals have been handed out.
"We don't want to jump about too much. Up to now he has done fantastically well. But the job is still there to be done."
The most notable aspect of Van Persie's arrival has been the ease with which he has settled into life with the Red Devils.
A goal on his full debut against Fulham in August clearly helped the process, as does a unified dressing room, according to Ferdinand.
"Winning the league is down to a group of players rather than one individual," said the former England star.
"But it is easy for people to settle in here.
"We have a great bunch of players and there is a great ambience in the squad.
"It is a great place to come to if you are willing to come in, work hard and be a member of the team."
There is little doubt Van Persie has done that, so quick has he been to share the praise for his own endeavours.
His partnership with Javier Hernandez has proved particularly productive.
Between them the duo scored seven times over the festive programme, presenting Sir Alex Ferguson with an obvious selection dilemma when Wayne Rooney recovers from his minor knee injury.
Not that either Van Persie or Hernandez is likely to start the weekend FA Cup tie at West Ham, given Ferguson has virtually an entire team of fresh alternatives to the players who started on Tuesday, with a crucial Premier League encounter with Liverpool looming immediately afterwards.
Even if Rooney's absence continues, Danny Welbeck and Shinji Kagawa can threaten the Hammers at one end, whilst, at the other, Ferdinand is delighted at the form which has yielded successive clean sheets.
"That was a nice feeling," said Ferdinand.
"The idea is always to win games, so the clean sheets issue has been put on the back burner a little bit.
"But we do pride ourselves on our defending and we are happy with two clean sheets on the spin."
Ten points from 12 over the festive programme represents a satisfactory return given City only managed nine.
However, after last season's startling collapse, when United lost a bigger lead in a far shorter space of time, Ferdinand is not wanting to let his focus drop.
"Last year was the first time City had challenged properly and there was a lot of focus on Manchester," said Ferdinand.
"But we have to make sure we keep our own house in order, make sure we keep ticking off the games.
"There is no point us focusing on anyone but ourselves."