TZ601 is a great all around tire, for qualifying and mains, specially on tracks that have a challenging inconsistent surface. The TZ601 is most often the fastest easiest tire to drive, and great for long mistake free mains. What you give up in laptime to TZ201 and TZ401 you make up in consistency.
The TZ601 is a large pin square lug tire that is designed to work best on dusty or loamy tracks, and rough tracks. It excels on dry high grip difficult, rough and edgy tracks, but also works well in damp or more grooved up conditions. The tire is designed with the large lugs relatively far apart, to maximise the ability to dig through dust and loose dirt. The edges of the tread are not only rounded, a special zigzag pattern is used in order to dramatically reduce the chance of the tyre cathing ruts and bumps.