Easy HTML and CSS abilities
All the things that are wrong with the Plesk Web Presense Builder!
1) It produces ridiculous amounts of non semantic markup code.
2) The negative effects of the non semantic markup code has on search engine optimization
3) In inability to fully customize the website templates
Untill these major issues have been dealt with Plesk Builder will remain a web designers absolute worst nightmare. Other than that its actually quite awesome and I really did enjoy the little time I had using it but because of these very important details I had to find another website builder to build my clients website with.
I would personally suggest cleaning it up! CSS should NOT be integrated with the HTML, there should be two completely separate files for both writeup languages. ALSO you need to some how stop the builder from spewing useless HTML and CSS code as well as allow the user the ability to completely customize the templete, I would absolutely love that. These are two of the biggest issues that should be worked on and should take first priority

We do not plan on introducing major changes to Web Presence Builder at the moment
—AK