I've never done a DI.
The reason being that DI's are quite expensive and the films that I've worked on to date, have not had an indulgent amount of money.
I do however, read alot about other dp's really liking the DI.
R Deakins for one, tends to use it all the time, by his own admission. To my eyes his work looks great!
Could it be that it is so popular as shoot times these days are so compressed. You can always correct something in the DI thus saving more money doing it that way, rather than sorting out any creases on set, which we are suppose to do, but requires more time.
The formula goes: more time = more money.
I suppose I'll only really work it out when I do my 1st DI.
Here's waiting....