It is a low-contrast, grainy film, that is ISO 1000 speed. The longer the developing time, the higher the amount of contrast and the higher the amount of grain.
It is visibly high in grain, no matter what. The Delta grain pattern simply makes the character of the grain very different from a random grain pattern, like one on HP5 or FP4. The grain is very neat (you might say "gridlike") and "washed over" looking, and sharp, not clumpy, random, and soft.
The way to make the grain less noticeable on the print is to enlarge less. One good way to do this is to use the film in medium format.
The important thing to remember is that it is ISO 1000. For standard exposure, set your light meter at 1000, and develop for normal contrast.
To get the least grain possible out of it, make sure you do not overexpose or over develop your film. These two things jack up the grain mightily on any film.
IMHO: Embrace the grain. Use it, don't try to defeat it. If you do, with this film, you will be fighting a losing battle no matter what.