Micron does make very good ram. That's not the same as making very fast ram though. Micron ram is great if you want chips that are widely compatible, very reliable, and fully guaranteed by the manufacturer. They're not so good if you want ram with a really large number on the label that might work at its rated speed in your motherboard.
Of course, Micron has made some overclockable ram too. The original Micron PC2100 was the king of overclocked DDR in 2001.