One idea is to setup 3 different ad sizes in adsense and then append only one ad to the site via javascript based on the browser viewport.
RT has set up six module classes that you can use to show or hide content from computers/tablets/phones. That way by appending something like "hidden-phone" or "visible-desktop" to the module suffix you can hide your slideshows, big ads, and other bulky modules from portable devices. I have noticed that even on a 1600px laptop, if I size the browser small enough, the Google Ads won't load. So Google must have a lower limit to screen size for showing ads. That's why they have separate mobile ads.
I created a new responsive grid for iReview template and it works pretty well.
But if we decide to include it in the new release, clients that wanted to be able to set fixed sizes to sidebar(s) will be unhappy.
With the responsive grid, you can only choose how many of the 12 columns will be used for sidebar(s).
Does RT template have any options for sidebar/content widths or grid column widths/gutters?
RT made some tweaks to Gantry and put the responsive layout over that. So the template admin panel is identical to previous templates. The layout tab still allows the exact same layout options for the Gantry grid as before. You can choose 0,1,2 or 3 sidebars.
1 sidebar: width-adjustable
2 sidebars: both width-adjustable to a lesser extent however both are always same width; you cannot have one narrow sidebar and the other wider
3 sidebars: not width-adjustable; all three bars are fixed width, take up half the width of the mainbody and are quite narrow, even on a wide screen.
After playing with my site for a while, I must say that JReviews responds very well to the responsive layout. The only thing that was giving me problems was the listings module with the _slideshow theme suffix. I had two columns set up with thumbnail width at 450px. On any screen over 1000px the thumbnail container would be wider than the image, so it looked pretty bad. So I just changed the thumbnail width to 600px and now only the largest screens affect it, and on smaller screens the entire module adjusts itself perfectly, resizing the thumbnail down and everything. I think this must be due to the fact that you guys (or the template) use img max-width: 100% for the images in JReviews, That is what allows the images to fluidly resize themselves. I would set it to 750px except for the fact that I have tons of businesses that have images < 600px so it wouldn't be worth it.