I haven't used CTR themes, but supposedly they are the best for adsense ctr.. I looked at their demo and all I see are skyscraper ads on the left/right of the content that could easily be done with a 3 column layout. What makes ctr themes worth the $60?
You can easily build your own themes based on their layouts. I don't see the benefit in buying theirs especially since I think they look like crap. You may want to checkout Clickbump Engine and their themes as they're highly customizable and at least look decent.
I can see no reason to use any premium theme. You can do anything the premium themes do with TwentyEleven (you might have to learn some CSS or pay for ONE gig at fiverr)
CTR themes helps increasing click through rate to your site by placing ads on such places on your site, which gets the most clicks. I've used couple of ctr themes in the past, including heatmap and clickbump, but none of them had helped me increase CTR than "adsense pro ultimate" ctr theme. I've been using this theme for over 6-7 months now and I must say it deserves credits, as it helped me increase ctr from 1% to 5-7% on most of my sites and now I make good money out of adsense. I've come across many threads on different forums where webmasters had great success using adsense pro ultimate. just take a look at this one (there are many others); warriorforum[dot]com/adsense-ppc-seo-discussion-forum/664519-poll-settle-once-all-ctr-theme-heatmap-theme.html If you are into CTR Themes, you might want to try them out first... EDIT: I am not associated with CTR Themes, so please don't accuse me!
I don't think they look very good either. You can do that with lots of themes. It's mostly hype. Adsense takes TRAFFIC and lots of it.
I think themes are not important as traffic. But you want to change your theme. You should try HeatMap Theme. Their deigns looks nicer. There are more space for advertising. So, GA will bring you more income. Nice,