The Cloudflow 4 is the fast end of On's trainer range. A Speedboard sits under Helion foam to give the forefoot some snap, and at 246 g with an 8 mm drop it is light enough to turn over quickly without feeling stripped out.
It suits you as the second shoe in a rotation: tempo runs, intervals, and shorter races where you want something firmer and more direct than a cushioned trainer. It is also a reasonable choice for a runner who simply prefers less foam underfoot.
It is not a long-run shoe and it is not a marathon racer. There is not enough stack to protect you late in a hard three hours, and the Speedboard here is not carbon. Keep something taller for the volume.