If it is raining or if in a hurry for a tight onward service when I am going from Euston to Kings Cross I usually get on the first bus from Euston bus station & use Oyster.
At peak times you could get held in traffic but I think my record one day last year was 9 minutes from arriving at Euston on a Pendolino to being seated on a 365 in Kings Cross departing from platform 7 which saved a 30 minute wait for the next GN service!
In the opposite direction I usually walk, as I have allowed longer to catch the VT service and using the bus involves crossing Euston Road twice (unless you catch the 59). if it is wet then I tend to use the Victoria line from Finsbury Park to Euston (as I would be arriving into London on a GN service).
At peak times you could get held in traffic but I think my record one day last year was 9 minutes from arriving at Euston on a Pendolino to being seated on a 365 in Kings Cross departing from platform 7 which saved a 30 minute wait for the next GN service!
In the opposite direction I usually walk, as I have allowed longer to catch the VT service and using the bus involves crossing Euston Road twice (unless you catch the 59). if it is wet then I tend to use the Victoria line from Finsbury Park to Euston (as I would be arriving into London on a GN service).