Memory leaks are definitely still there on some PCs, but not all. I have 16GBs of DDR3 RAM and I can clearly see on my memory monitoring software RAM filling up as time passes. Depending on what I'm doing I may need to restart the game after as little as 30 minutes, but usually around an hour, otherwise performance suffers. Big battles are the biggest culprit, but if I have loads of items in my inventory, even opening and closing it noticeably increases RAM use, and each time some of it never gets flushed.
I have started using CleanMem to clean my memory mid game to help with the issue which works to some degree, BUT... the game seems to be writing a lot to my pagefile (virtual memory), which I cannot clear without restarting. So even if I clean my memory and cache, the "commit total" value remains over 16GBs, affecting the performance and continuing to fill up.