Persona 4: Arena on Xbox 360 reported to be extremely laggy

Kubo's main game is Persona 4 The Ultimate in Mayonaka Arena and is famously known for discovering the Kubota Escape glitch in UMvC3.
Here's a quote from Beast Note.
Kubo bought both PS3 and Xbox 360 versions of P4U and tried the online play on his stream. The 360 version had an unplayable lag (heavy slowdown). He tested with 4 different users. He also tried switching back and forth to training mode. The problem was really the online play.
He then tried the PS3 version. The online play was okay on PS3.
You probably know Kubo as an UMvC3 player, but when he goes to the arcades, he plays P4U as main game.
He then tried the PS3 version. The online play was okay on PS3.
You probably know Kubo as an UMvC3 player, but when he goes to the arcades, he plays P4U as main game.