Do you know why the main body - which includes the tabs of the property detail page - gets loaded so slowly? Is it because of all the pictures have to be loaded first?
Isn´t there any other possibility that the picture gallery gets loaded after the main detail property page is displayed?

In the demo, I use slideshow_fancybox plugin with 10-20 large pictures (approx 600-660px width) for each property. As you may already know, plugin doesn`t generate thumbnails, they are loaded in full. There is also the google map which is loaded depending on how busy the google maps servers are. Together, all this can make the tabs load slower than expected.
The tabber.js used in Jomres has an option to use ajax for loading tabs content (the content is loaded only when clicking on a tab; default tab is loaded from the beginning). I`m not sure this will work with jomres, but it worth giving it a try..