I would rate the vada pav 5 on 5.Because it's the most famous vada pav in areas of sion,matunga,chunabhatti and dadar and many more.This famous vada pav is actually inside the school known as amulakh amichand.It's as cheap as Rs6.But it's oil free and believe me once you eat you won't forget and come again and again if the security allows you.
It's a school canteen after all.I would say that it would beat any other vada pav chains any time.Have a try and definately you will love it.