I don't think the orange boarding scrum is an issue if you use speedy boarding. In fact, this product has a premium over BA as you use a dedicated check in aisle, bypassing the queues.
It is very rare to be bussed to the aircraft (especially LON-BCN) and even when you are, if the aircraft is busy to the point where seating will become an issue there will be two busses, meaning you still get an excellent choice of seats even if you are the last to get off. Personally I have NEVER failed to get a window seat on an easyjet flight.