I don't know, I think on the distinctions and accuracy of the terms "penal", "heroic" and even "strategic" that their various charateristics apply pretty well and are quite clear if one uses them as they were meant to be used. So the definitions really shouldn't be particularly fuzzy.
I think Mark Fine described the distinctions and definitions very well above, certainly between "penal" and "heroic".
Penal is definitely a feature or concept where mostly distance alone and quite a lot of it generally in a perpendicular, all encompassing, no option or very low option sense is brought into play as the feature of the shot or hole.
Heroic almost always should be considered a feature or concept where both large VARIATIONS in certainly distance but also degrees of angle are used.
About the most naturally best looking, probably the most effective and maybe the best example of a herioc shot would seem to me to be #5 Mid Ocean. The hole is famous mostly for that very thing, I'm sure. I've looked at that hole for a long time to see what exactly it is about that angle or diagonal that makes it so great. I think I decided that much of it has to do with the fact that the gentle diagonal (the shoreline) starts well to the RIGHT and below the tee, so there is something to carry! But the gentle diagonal of the shoreline/fairway is so confusing to estimate, and additionally is either aided or made more confusing by the height of the tee! But the diagonal is so gentle that obviously a very slight variation on the tee shot's accuracy translates into a large need (or not) for distance of carry. Certainly this tee shot is one of the best examples in golf of "herioc" but the point is the tee shot hardly has to be "penal" at all if you choose it not to be. Far be it from me to think of some kind of conceptual improvement to a world class hole but just think how much more meaningful and tempting this particular tee shot would be and could be if somehow the green on this hole swung well left off the fairway/shoreline diagonal (at maybe a 45% angle). This would make the need for more distance on the tee shot much more important. But McD. simply used a natural shoreline and green site all the way along just the way it was, so what are you going to do?
Some other great examples of one degree or another of diagonal to create some great "heroic" shots and choices that don't have to be "penal" are Merion's #5, Pebble's #18, Seminole's #15, Maidstone's #7, #17.
Then some other holes that can be very heroic with wide variations of distance and small degrees of angle but just a bit penal using other features and concepts are NGLA's #1,#2,#7,#17,#18, GCGC's #1,#2!!,#11 and some of the others Pat can explain better than me. Seminole's #3, #6, #16, #18 and of course many many great classic holes that are too numerous to mention. But they are all good examples of how holes and shots can be very "heroic" but not particularly "penal" if you don't want them to be which makes the distinction in the terms quite clear to me.
I will mention one last hole that has all kinds of things going for it including extremely interesting degrees of both "heroic and "penal". It's Easthampton's #11 and I'm told Bill Coore's favorite. It's a very short hole whose fairway cants quite a bit right to left towards bunkering and high grass left (penal) that is all set on a gentle but brilliant diagonal from the tee. Add to this that the green is set over to the left enough to pull a golfer's aim from the tee at it! Add to this that the end of the diagonal on the left is blind to the strong golfer on the tee. And the real kicker is unless someone is almost going to try to drive this green it might not make that much difference where you are on the fairway, although it sort of appears in everyway that it does!!
With holes like this one and certainly #17 Easthampton it definitely appears that Coore and Crenshaw have come up with some of the most clever ways ever known of getting into a golfer's head bigtime with the uses of angle, green orientation, sizes, shapes, elevation changes and almost anythng else you can think of including in one brilliant case a NUMBER!
Got a little off the subject there but I agree with Mark Fine, it's quite clear to me the distinctions between "penal" and "heroic" and their separate meanings.