Though, shouldn't it have taken the Enterprise several days to get to Kronos?
(For that matter, Vulcan should have been a day or two in the 2009 movie)
If we go with the idea that the initial scans of the Narada
by the late Starship Kelvin
led to major technological changes in the new timeline, then the warp drive of the nuEnterprise
may be more than a century ahead of what it was originally.
But it could also be said if it only took NX-01 four days to get to the Klingon homeworld, a significantly faster NCC-1701 should get there in a fraction
of the time and to Vulcan in even less time.