WPS 6.1.5 introduces a new theme called Enhanced Portal theme, which introduces lot of new features such as page builder,...
One big change in the enhanced theme is that it makes use of DIV + CSS instead of tables. I am not expert in HTML so i did search on google to find out what is difference between div and table and it seems that there are quite few articles that list out problems with table layout, things like the table layout is difficult to maintain, CSS should be used for managing layout instead of table, some stack overflow problems in the browser,..etc. This is one of the article
I tried using firebug to see the difference in traditional theme and enhanced theme. I did apply it to same page and then outlined all tables using Web developer plugin.
This is screen shot of the enhanced theme
Screen shot of the traditional theme
As you can see the enhanced theme does not make use of the tables for layout as heavily as that of the traditional theme