For me this item is perfect in the 35 to 45 F degree range, keeps my ears warm but lets my head radiate some heat out of the top. Packs super small so it's easy to carry.
Have really liked the Garneau Hugo Headband this winter. Unlike some other ear bands I've tried, the extra width of the Hugo ensures you get full coverage over your ears and it does not slip out of place while you ride - no cold earlobes. Unlike a cap, the top is open so you get better heat dissipation. Have found to it is best suited to temps in the upper 40's to low 50's.
