The best part: it gives you a consistent spacing [0] and a consistent font scale [1] which is relative to rem. No more magic values, just use classes:
ma0 ... ma7 margin: 0|0.25|0.5|1|2|4|8|16 rem
ml|mr|mb|mt [0-7] marginLeft, marginRight, marginBottom, marginTop
mh [0-7] marginHorizontal
mv [0-7] marginVertical
/* Same with p for padding */
No more stylesheets, everything is there at a glance and easily fixable: <View cls="bt bb jcfs pa2"> /* border at top and bottom, justifyContent: stretch, padding: 0.5rem */
<Text cls="white tc"> /* white color, text-align: center */
Something
</Text>
</View>
[0] http://tachyons.io/docs/layout/spacing/