Have not sat in the new Honda so in I can not compare the 18 models.
For me stow and go was a must have feature. I needed a car that can fit 5 people, but I also need a truck. With stow and go I have fit full sheets of plywood in my van. I just remodeled my basement and would have had difficulty doing so without the van.
Also when comparing the 17 models the Pacifica had
1. A front latching point for rear facing car seats in the bucket seats, no other van had this.
2. The bucket seats fold forward allowing easy access into the back with car seats in the bucket seats (however I would argue the new Honda mini van does a better job with this.)
3. Two car seat latch points in the back, not all vans had this.
4. The 17 Honda still had the sliding door tracks, really Honda it took until 2018 for you to fix this.
5. The 17 Honda has a smaller front driver seat area, I was not able to push the front seat back far enough to fit (I am 6'5")