I have some HP branded CMC MAG. AM3, and I have burned these in most of my drives.
I have a NEC ND-4551A which is identical to the 3550, except for DVD-RAM and LabelFlash support, and the burn quality is not good in my opinion.
The PIE/PIF levels of the burn are quite good, but the disc has reading problems in my BenQ 1655 drive which is the pickiest of my drives. Since reading is far more important than pretty PIE/PIF graphs, I consider the results to be poor.
My BenQ 1655 burns these discs with good quality (SolidBurn On, WOPC Enabled).
To be fair, my NEC 4551 can also burn high quality media such as Taiyo Yuden in a way, that causes some reading problems in a BenQ drive, so I'm not actually blaming the CMC MAG. AM3 media but rather the NEC drive for being a quirky burner and the BenQ drive for being a quirky reader.