Ha, I found my own old topic when I was searching for a little annoyance 
So I just realised (again) that the actual images that are loaded are huge compared to their actual rendered size. In my case, it’s loading 1000x1000px image and rendering them at < 200px.
I checked some of the data, and if I could replace them with the 400x400px version, that would save around 83% in bandwidth (for the featured row), or 1.6MB total. I know these images are cached, but this will definitely make an impact on the initial page load and I suppose it also won’t help with speeding up page rendering? I’m using these featured images on every page on my forum, so I think the impact is real.
Would it be possible to add an option to the configuration of the TC to let us choose which image size to use, so everyone can tweak this to their own theme?