Last night while boarding a United 757 in Chicago (using the front
door for everyone), the gate agent asked for our co-operation because,
as she said, the 757 is an awkward plane to board.  This was the first
time I had been on a 757 boarding at the front door (United boards
757s at the middle door in Toronto) and it was awkward and slow.  How
much attention is given to boarding in the design of aircraft?  Is the
757 particularly bad or was I setup for seeing this by the gate
agent's comment?  Did the 757 design intend that the normal boarding
be by the mid-door or the front door?  How many airports are setup to
handle mid-door boarding (Toronto has movable Jetways - but slow to
get into position, while Chicago has fixed position Jetways)?