Drop box Vs In -person interview for Visa stamping ( DELHI)

Hi,

I am planning to travel to DELHI during JUN-JUL period

I qualify for drop box for my visa stamping this time but few friends told me that they are sending you AC-221 forms and it delays your stamping time.

Is it true? Shall I go for in-person stamping process then?

My case is not complicated. I am a full time employee of a big firm in USA and had been with them forever.

Thanks

Parul