Cool....You have the same type of ceiling I have...The No-Squeak I-Joists.
I thought about drywalling the ceiling, but with the amount of cables I have up there (all my whole house audio/video/automation), I think I'm going with a drop ceiling.
Nice job on the riser with couch. I've been toying with whether to go with a couch or more recliners on the 2nd row. I think I'm going with a couch so that I won't need the extra space for reclining, and I can put a bar behind the couch with some bar stools for overflow seating.
Good Job!