I think there is a difference, but it's quite subtle. There's a certain sumpin' sumpin' that German pils malt has over domestic pils. I prefer to use authentic ingredients for my brewing, but I don't know if it'd matter much in something like a schwarzbier. I do typically use Rahr white wheat for my hefes though...so I wonder much different it'd be with something like Weyermann or Best. Guess I'll find out since I've got a sack of Best wheat comin'. My guess is it won't be much different as hefes are mainly driven by the yeast.