1. You have mentioned that 13177/78 has good slack. It remains as it is with conventional rake as well.
2. As far as the facility of toilet goes, I think ICF coaches have way better in 4 toilets per coach.
3....
more... 12 coach rake behind a WAP - 4 is not a bad deal, IMO.
4. As I have already mentioned, I would have been happier with ICF rake for Godda - Sealdah.
5. I checked the running status of 13177/78 for today's run and I see no significant delay at either ends.