Anthony -
I'm guessing that most of the those who don't like forced carries off the tee (and I'm one) would say that, if you're going to have forced carries, make the carry-distance shorter rather than longer. I disagree - I think they work best when the carry-distance is longer rather than shorter, i.e. long enough so that it is a legitimate test of whether a given player can hit, on that particular shot, the kind of golf shot he EXPECTS himself to hit...and at the same time, long enough that the player who decides NOT to test himself that way (with the carry) isn't left with a punishingly long approach shot.
On a, say, 390 yard par 4, a carry/crossing hazard at 230-240 yards (with the prevailing wind) seems about right. From the appropriate tees, a decision -- try to carry it, and you have about 145 left; lay up short, and you have 170 left. More important, I think, is what's happening at the green, i.e. whether or not the lay-upper can at least roll up a long iron/hybrid through a good siee opening, and at least somewhere onto the green (if not the ideal place/side)
Peter