Well Commuting for over a year on my ebike. My commute 1 way is about 12 miles. I went from 90-100 mins to 45-55 mins depending on the level assist that I use. I switched to an ebike to eliminate the variation in time commuting.
I tend to use level 2-3/5 (500W Hub Drive) on my current bike. Level 2/4 (350W Mid Drive) on my old ebike. I use google maps, they calculate speed at around 10 mph. I've never used level 4 or 5 exclusively. I use Level 4-5 sometimes when I'm on the road trying to get home faster. The last two weeks, I haven't been commuting because I got an ingrown toenail removed and am trying to heal. I hope that this helps.