My question is fairly simple. If I have a normal latency to WoW of 50-60 during the day and 400-600 during the evening, is the issue more likely to be on my end or Blizzards? (I have run the leatrix fix). These symptoms cross multiple servers and characters.
First, check on a site such as www.speedtest.net at both times (when your latency is high and low) to see if it's just down to WoW.
Check to see that your network is secure, that nobody is connecting to your wireless without your authorisation.
Check also to see if anyone in your household is running bandwidth consuming applications at those times (torrents, downloads, watching online video etc).
I just checked the dhcp table and the only two connected are my wife and I. Neither are using wifi. We do not have children, so no one is downloading etc.
Many people have been having latency issues from 4pm-12am for the past couple weeks. From what I've read it's the ISP that the WoW servers use, not the individual persons.