Personally, I think "premium ammo" gives folks a false sense of security. No ammo's going to save you, buckaroo, your shot placement will.
Or they use the "my life is worth it" line. Well, of COURSE your life is worth it, so travel with an armored division at all times!
If the WWB ammo has been shown to not reliably expand, and do it's job, then I'd stay away. But all tests show it works well. Maybe not quite the numbers that the "premium ammo" puts up, but that's IMO nullified by the fact you can shoot it all the time if you want due to low cost... and the fact you'll score more precise hits with what you typically shoot.
It's like the guy who shows up at the range with the Wilson Combat .45 but can't hit the broadside of a barn. Is he really better protected than the kid with the shagged out LEO-tradein Glock that can hit 5 tiny circle targets on one page?
Now, if you want to shoot premium ammo as your practice ammo, do it! I personally am comfortable with the WWB.