From the descriptions provided on the Hilton Hotel website, it appears that Seaworld studios do have a sofa-sleeper, but I-Drive studios do not.
Here are the quotes:
SEAWORLD - 1 QUEEN-KITCHENETTE-STUDIO
"... Each studio offers a 27" TV, DVD player, Hilton Alarm Clock Radio with MP3 connection, sofa sleeper, wireless high-speed Internet, phones with voice mail, in room safe, wet bar, small refrigerator, microwave, coffee maker, toaster, dishes and utensils."
I-DRIVE - HILTON GUEST RM-1 KING BED
"... Each studio offers a 27" TV, DVD player, Hilton Alarm Clock Radio with MP3 connection, wireless high-speed Internet, phones with voice mail, in room safe, wet bar, small refrigerator, microwave, coffee maker, toaster, dishes and utensils."