Though the Jumbo King Vada Pav is really tasty and well-packed, they need to at least ask us if we want the Chutney/ketchup spread inside like the regular vendors. It is so inconvenient to open the chutney zip locks! Overall, it is a very good concept-only that you need to look out for an outlet. I am not sure how much one can wait to spot a JK outlet if one is hungry.
Another good thing about JK is that it uses the roadside rather than inside-the-mall space that McDonalds or Subway etc. use. This makes it really easy to pick the VP on the go, without the prospect of entering a crowded mall.
Im not sure if they do, but they should also stock water and soft drinks and anything that complements their core offering-the Vada Pav. For me, a VP is not a convenient option to satisfy my hunger if something to drink is not available at the same or next stall. JK, with their setup, can definitely note and work on these points.