I am in the camp that the first hole should be moderately long to keep play moving, but the features shouldn't be back breakers.
For example, on a current remodel, I have put chocolate drop mounds right of the green instead of sand to right of the green as a small concession to speed of play for the average players who populate the course. The green will be relatively flat, as well.
On the other hand, I can also think of several first holes on my designs that aren't really much different that other holes difficulty wise. I put spectacle bunkers in front of the first at the Quarry, because I had never done a green like that before, and the first at Indian Creek in Texas has a bunker patterned loosely after 10 at Augusta, because it looked right. Fortune Bay starts with a plus 600 yard par 5 with double fw at both first and second landing areas.
Those did well in the "Best New" rankings. I think the ratings game kind of drives more exciting first holes than in days past. Given that raters typically rate based on one visit, and knowing that in a speech, I have (statistically) 17 seconds to grab an audiences attention or lose them for the entire presentation, I have to wonder if starting out with some kind of "wow" is necessary to attaining good reviews these days.
Just an idle, before coffee sunday morning thought.......and tomorrow, I am going out to that project and "punching up" that first hole!