Yeah it's just personal preference I guess. A lot of people swear the extra four hours per day increases yield which would make since. I deffinatley notice the smell gets way stronger after lights off though. Maybee the terpenes develop more idk. I got the dry weight for my fast and vast it was 65.2 grams not to bad considering it was my first grow after a year and a half break so I was a little rusty and I only had one panel over it the other panel has been over my red poison. Now the red poison gets both lights so she should yield a little bit more.