Interesting! I've been lead to believe that D76 yields the clearest negatives, which is pretty important to me. As for HC-110, from what I can see off of Flickr, people seem to be getting the clearest results with dilution B. Apart from the concentration amount, I can't figure out what it is that makes it so clear sometimes and then other times, it's grain all over the place! And don't even get me started on the Tri-X curl, it's almost cruel!
As for this current roll of HP5+ I have, what would be the best way--using Rodinal in order to get a less grainy negative? Loss of contrast is fine, as that's nothing Photoshop can't fix up in half a second.