Upfront Builder very slow when updating or creating site pages.

Because your plugins have been working so well, usually, I decided to switch over to one of your themes and use Upfront Builder. I am not sure if that was such a good idea. The Upfront Builder runs very slow, is clunky and freezes up quite a bit. It doubles or even triples my design and update times which is not good. I currently host on Hostgator and have spoken to them regarding the speed of my edit time and was told the it was not on their end and to contact you. So here I am, looking for some help and input that could resolve this issue and forego me having to start over using Visual Composer; Which by the way worked much faster and offered more options than Upfront Builder. My main reason for switching was to keep using the same WPMU apps across the board on all my sites for compatibility reasons and only having to pay one fee each year. Question? Could I use Visual Composer with your themes?

Looking forward to your help .