[KTBleeding]

When comparing the two, there isn't really a "better or worse", but both of them are very different from each other..

You'll need to figure out what is more important to you for what you need. While there are workarounds, the back button doesn't work in XHR (AJAX) by default, but it does allow you to simply create a new remote request..

I mean, it all depends on what you are using it for, I suppose. I suggest reading into both of them. Maybe even look up a few comparisons to find better answers to your questions.

I have no idea about the mobile phone stuff, I always give my visitors nothing more than an html display of content and navigation on mobile devices.