90 mins vs 60 mins meditation mostly Anapana

I've been meditating for 1 hour, and I'm planning to extend it to 90 minutes. Will there be any significant change in my experience? Has anyone had a real experience with this? Follow up Why everyone asks to do twice , not once a day? In vipassana 10 days retreat they asked not to go beyond 60 mins as it will lead to different state. That's why I asked. Why it's getting more and more difficult if I am increasing duration?