<p dir="auto">Is it just me or does there appear to be serious inconsistency between the size breaks for cols and hidden/visible?</p>
<p dir="auto">Shouldn't col-sm- really be col-md- (and col- is essentially synonymous with col-sm-)?</p>
<p dir="auto">With Bootstrap 3 RC1, the <code class="notranslate">sm</code> keyword is used in an inconsistent manner. When referring to column sizes, it means "tablet sized." When referring to hide/show responsive classes it means "phone sized." My recommendation would be to rename all of the <code class="notranslate">col-sm-X</code> classes to be <code class="notranslate">col-md-X</code> classes.</p>
<p dir="auto">This would solve the inconsistency while still advocating "mobile-first" and leaving the mobile columns un-prefixed.</p>