Thanks for posting with your issue, I’ll be happy to help.
It’s very unusual that you’re getting more consistent performance over wifi than through the USB2-E1000. My feeling is that this sounds like a networking issue, so my recommendation is to look into your connections a bit.
That said, if you get tired of troubleshooting and want to try a pre-tested replacement unit to check agains the possibility of a faulty device, just shoot an email with a link to this post, attention Jeff, with your Amazon order ID, shipping address, and the serial number from the unit to email@example.com.
There are a couple of other details that might be helpful in troubleshooting, like what sort of server you’re streaming from (is this some XBMC or Amahi Home server, or other DLNA device, or other), as well as what sort of network you’re on at home.
I’ve also seen similar issues where a certain port in a switch or router was faulty, resulting in performance issues on whatever device was on that specific port. Switching to another port on the hub/switch/router you’re wired in to, and/or eliminating additional upstream network devices like these can also be helpful in isolating network issues.
I hope this helps, but please let me know if you’ve any other questions.