I'm running a Macbook Air (2011) right now, and considering a 13 in MBP and the new Macbook. If I bought the dongle that is $79, it would allow an external monitor (HDMI), charging, and the USB port. Since I have a USB to ethernet, do you think I could use both adapters together to get ethernet working on the machine? And if it DID work, would I be looking at slower ethernet speeds do you think?