i'm agonna go ahead and say that generally...if its just everyday sex...it'll be the guy who gets his and then just goes into shutdown mode.
now, this has never happened to me (orgasm, then need sleep immediately) except for one time when i had stayed up 48 hrs straight. she was horny as hell so i gathered myself and did my duty. no sooner had she finished her moaning than my head was glued to the pillow and i was out COLD.
if she wanted to cuddle....go ahead, i just wont be concious