I won't run a -5 out of principle (mostly because of how glitchy it was in the past), but if a team just refuses to shoot threes, I have no problem running a -3 or -4 and have had a lot of success in those instances.  I've also ran +3's and +4 against teams that jack up threes like they're going out of style and have had success there also (although not as much success as I think the setting should produce).

In short, I think all defensive settings are still viable given the right situation.  Oh, and my two cents here, when I take the time to actually gameplan, I usually end up on the good side of the score.  It's when I don't gameplan that I end up having problems.  I think it still matters enough to make a difference.