I think webflow is possibly the slickest responsive website builder out there right now. There is an issue with how it interprets Knack's embeds though. After a bit of hair-pulling I figured out that it has to do with Knack not automatically clearing after each view render. Rather than enter every single view selector into the webflow css editor you can use this simple script. Hope it helps someone.
$(document).on('knack-view-render.any', function(event, view, data) {
var key = view.key;
var selector = '#' + key;
//console.log("selector key : " + selector);
//console.log("view Key:" + key);
$(selector).css('clear', 'both');
});