I tend to agree with you Steve.
I took both my GPZ and 6k out a few days ago. The day before the 6k got real noisy, to the point it couldn't be used . I put it down to the 11" mono and the next day I took the 14dd, and planned to use it if the GPZ was too noisy. Well the GPZ handled it no problem. My mates 6k did not however, and he changed to the 14" dd which was still noisy!