Vegeta's statement "Since when is the difference between Kakaroto and me so great"?

[SIAD]

Vegeta's statement "Since when is the difference between Kakaroto and me so great", it means that the gap between Goku SSJ4 over Vegeta SSJ2 at that time is higher than the gap between Goku SSJ (Namek) over Vegeta (End of Arc Namek) ?

 

[Spiral-Force]

Are you referring to Ep 55?

 

[Captain Cadaver]

Are you referring to Ep 55?

That's what I'd assume.

As for the topic, leaving aside the fact that even the slightest difference between characters that are Galaxy to Multi-Galaxy level at this point should be astronomically greater than those during the Freeza Arc regardless of what the inconsistent battle power system would suggest, I wouldn't say the statement literally means this is the greatest difference that's ever occurred between Goku and Vegeta. Vegeta had always shown the ability to catch up to Goku through his own training, yet had consistently lagged behind Goku all throughout GT and SS4 wasn't something training alone could grant him.

 

[Spiral-Force]

In that case, to answer the question:

It's doubtful that Vegeta was thinking that specifically. He was just taken aback by how much wider the gap between him and Goku became, which was already quite significant. Vegeta tends to have heated moments when Goku achieves a transformation above his own capability (e.g. his reaction to SSJ Goku when he first came back to Earth, and his anger about Goku hiding SSJ3 from him). Other than that, this moment illustrated how an obsessive thought is still capable of creeping into one's mind from time to time, no matter how much the person tries to move on from it.