I have trouble finding auditory fault with the Premium, even with my compressed iTunes music. As a matter of fact, if the B&O didn't exist, I think I'd have trouble finding fault with its looks as well - the plastics are very high quality. However, the B&O does exist, and it makes the Premium look boring by comparison.
If the sound quality is truly the deciding factor, then listen and see what you think. If the B&O looked identical to the Premium, there is no way I'd pay the extra money. But it doesn't - it looks exclusive, sleek, and modern - perfect for the F12/13. You pay a premium for some B&O-engraved tinsel, and I think the value if that to the buyer is a major factor.
Sounds shallow and superficial, but I think that's the case for to those of us who aren't true audiophiles (defined as those who would pay $3700 for a visually identical B&O system).