Whether Arsenal fans view him as a traitor, or see his departure a symptom of wider failings at the club, what can't be denied is Robin van Persie's relentless goalscoring record since around the time of January 2011.
In his final one-and-a-half seasons at Arsenal, he scored at a phenomenal rate, netting 18 goals in his final 18 league games in 2011, and then 30 in 38 in 2011/12, winning a PFA and Football Writers Player of the Year award double.
Since moving to Manchester United, he has carried this on, scoring 26 league goals in 38 games as he inspired the Red Devils to their 20th league title.
His departure from Arsenal was only confirmed in mid-to-late August, leaving little time to go and sign a replacement - having to make do with Olivier Giroud and Lukas Podolski who it was claimed were bought to support the Dutchman.
This summer Arsenal are dead set on doing just that, with rumours hotting up that they are in pole position to sign Gonzalo Higuain from Real Madrid, with Juventus struggling to raise the cash.
If they do land the prolific Argentine, there can be little doubt about whether they have replaced the Dutchman, indeed his name will be consigned to the past at the Emirates.
But will trading in Van Persie for Higuain - at the cost of a season in between - actually result in a better outcome for Arsenal?
Firstly and most importantly, Higuain is four years younger than Van Persie at 25, and could theoretically be banging in the goals for the Gunners for the next decade.
Secondly he has no such troublesome injury history as the Dutchman. He missed a month of the season with a muscle injury at the end of 2012, and missed half a season with a back problem in 2010, an issue which hasn't recurred - Far more favourable than Van Persie's littany of past issues - which cause fans a panic every single time he went down from a challenge.
Turning 30 in August, there still remains the fear that a serious injury could be disastrous for Van Persie's long-term future, whereas Higuain would have greater time to recover from any setback.
If they hadn't sold Van Persie - it's doubtful they would be looking at Higuain now, and differing given the time both players have ahead in their careers, if Arsenal complete for Higuain it might see them overall in a better position.
From a goalscoring point of view, Higuain certainly measures up to Van Persie - and can even be considered better as a goal poacher.
He netted 16 in 19 La Liga starts for Madrid this season, plus a further nine substitute appearances, the previous season scoring 22 goals for the club.
His best season remains the 2009/10 campaign before Mourinho, under Manuel Pellegrini, where he struck 27 La Liga goals in 32 games. In fact in La Liga, since making his debut, only two players have scored more goals than him- Cristiano Ronaldo and Lionel Messi - a duo there is no shame in finishing third to.
Whether he will be able to strike up the same sort of rapport Van Persie had with his Arsenal teammates, is a challenge for him, but it will not just be about individual success.
If he signs for Arsenal the greatest barometer of his success will be whether he can lead the team to do what Van Persie couldn't - win trophies.
Will Higuain be an upgrade on Van Persie? What's your opinion?
image: © dundasfc