Hi Roger,
Great question and I'm really sorry to answer it late - my mistake due to a mix-up. Might be too late for you, but anyway:
While Joomla! 3.x uses the Bootstrap framework, it doesn't really optimize the delivery of your website data to mobile devices - all browsers have to download the same resources. And the page size obviously affects your site's loading time, which greatly affects your mobile bounce rate. In our tests, oftentimes sites would perform 100-400% faster on mobile using server-side optimization (
www.mobilejoomla.com/blog/157-400-faster-responsive-joomla-templates-with-mobile-joomla.html).
Mobile Joomla! can also optimize 3rd party responsive templates (just select the template of your choice in Mobile Joomla! admin settings), it:
- automatically delivers each device the right image sizes so your mobile visitors don't have to download desktop-size images
- you can prevent certain (e.g. desktop-only) plugins/modules from mobile views for better user experience (not just hide them, but actually prevent them from being even send to the mobile device -> faster loading)
- Our premium templates Flat/Elegance include advanced features like improved Lazy Loading (
www.mobilejoomla.com/blog/211-welcome-lazy-load-xt-for-jquery-images-videos-media.html), as well as combines your JavaScript and CSS files and minimizes them for smaller size and fewer HTTP requests (each HTTP request means delay due to inherent mobile network latencies;
www.mobilejoomla.com/blog/172-responsive-design-vs-server-side-solutions-infographic.html)
- The JS/CSS combining is also included in upcoming MJ2.0 (Alpha just going out to first testers)
Cheers,
Miikka