I believe the radajaxpanel and radxmlhttppanel somewhat serves the same purpose. When performance is considered, which control is
preferred especially when dealing with client side data loading?
The RadXmlHttpPanel's panel is able to provide better performance because, unlike AJAX,
ASP.NET Callbacks do not go through the entire page lifecycle, but only through
a small part of it. The data, returned from the server is also significantly smaller than the typical
AJAX response -
it is the data needed to update the content of the RadXmlHttpPanel only. No hidden variables,
such as the ViewState content, are returned.