Colleague as first officer watched as captain began take off roll at Melbourne runway 27 in B737-400. Although the crosswind was only 25 knots the captain used full into wind aileron for the entire take off run. He later said he always used full aileron into wind above 15 knots. Around 115 knots (VR 135 knots) the acceleration slowed markedly and it was obvious the take off run was going to be critical. All the runway was used when the performance calculations showed ample runway was available.
The increased spoiler drag became readily apparent as the aircraft neared VR.
Regardless of "padding" designed into take off performance tables there is definately a serious increase in take off distance with full crosswind controls applied.