Whenever I go to Holborn, I usually come in on the Picadilly line. I'm so obsessive about getting the right doors for stations, that i'm normally one of the first out - so don't have problems too often - but the problem is the first escalator. There is only one escalator going up, and 80% of people want to stand, so there can be congestion here.
I walk up the first escalator which is pretty long - but I don't normally have it in me to walk up the second long one to the street.
The thing is, there are 4 escalators at Holborn to/from the street. How about:
2 go down as normal (lots of people tend to walk down however long the escalator is)
1 goes up as normal
1 goes up with people on both sides
(To be fair, I only ever go to Holborn after work or on weekends - not sure how this would be in the morning rush)