It's not a matter of "better". I'm just stating my own mode of thought and preference. My hunch is that Delta 400 was designed to fill a journalistic niche with a relatively forgiving low-light film having a pronounced S-curve. This accounts for why D400 tends to render a bland look under certain circumstances - it captures a wide range, but only the central portion of the curve has decent textural separation. Those who gravitate to its use no doubt do so because they are working with kinds of subject matter and lighting favorable to this particular film. I just don't like its look in print fashion.
But I do love what D3200 can often do, plus you get at least a full stop or speed EV boost above Delta 400 by rating it at 800. Rated much higher than that, however, then you're liable to coast way down on the toe, and potentially end up with the same shadow blandness as you got with Delta 400. One needs to keep in mind that "3200" is a marketing speed, not the official speed. You can shoot it at higher speeds than 800 or 1000 - you'll bag "something"; but what will be the quality of those nether regions of the tonal scale, comparatively?