There is nothing new or astonishing in Bluedarts timing and quality.But You get what you pay for.
I have used Bluedart 10-15 times to send a courier to the same state as well as other states, Believe me Sometimes they delay the delivery too much and sometimes it reaches to the receiver much faster then the estimated time.
I dont know why it Happens, but overall Its a good Courier Companies which does its job and is far better then many other companies.