Hey Paul,
Ours isn't too bad.
http://ukxxxpass.com. I opted not to use Bootstrap (or any other framework) and try and just make it manually. To cut down on the overheads etc.
That said, I looked through the HTML/CSS the other day and its an absolute abortion! Christ only knows how it still works!!!
One thing I did do is hack the PHP part of the CMS so it delivers different VOLUMES of thumbs depending upon device. I.e. on small screens where only a single column is practical, I throttled back and only show 8 thumbs (I think.... might be 12). on larger screens that volume goes up.
That way, you'll help contribute to keeping your google pagespeed nice and quick, and we all know G loves quick sites!