I sort of like the new website (although that review bar is TERRIBLY annoying and can't be hidden), but I agree it's too much of a strain on slow computers. The ones at my uni's library FREEZE while navigating OCN.
And I do see an increase on resource usage while browsing. Chrome memory usage has also skyrocketed. 200MB (for the OCN tab), it won't go under that.
I'm sorry to say that the new layout (which is lovely, besides from the login popup and the reviews bar) doesn't make up for the performance hit we're seeing...
When scrolling down posts I easily see my CPU usage go up to 20-25% in long posts. Skyrim loads a 30%, go figure.