I agree with Ex, 48 hours non stop would be great. Each team would have a base to retreat to for rearming and reloading, with command posts that can be captured and occupied. The whole field would be in play, no out of play areas to "take a break". It would definitly be test of organizational skills for the host, keeping objectives and missions going to keep everyone in the fight. I'd be up for it, and I think the player cap should be kept low to have quality players over a quantity of players that will get bored/tired/lazy.
Tpr. Spencer, DF
RCD C Sqn - CFB Gagetown
Please save for me, some gallantry
That will echo when I'm gone