I just purchased a 2014 Buick LaCrosse 3.6 w/premium II package. For the price I finally bought the VXDIAG VCX NANO GM box hands down over the Tech2(clone or original).
I got the WiFi version here: http://www.vxdiagshop.com/wholesale/vxdiag-vcx-nano-for-gm-opel-wifi-version.html
The WIFI does work, but I did not hook up by using it. The VCX shows up on the available WiFi hot spots on my laptop so I guess that it send information that way. However, I was testing module features on my 2014 Buick LacRosse so I did not want to just rely on a wireless connection that could fail midway through an diagnostic test. Plus, I was sitting in the car with my laptop so I do not see the point of using wifi two feet from the OBD port.
I will test out WiFi soon to see if it really does work reliably.
Here is some pictures of the VCX menus.
The VCX device manager that allows you configure it for USB or WiFi connection.
The VCX as a WiFi hub
Here is the laptop connected to WiFi VCX connection.
The GDS2 software that has to be put on a Windows 7 native machine or a Windows XP virtual drive.
It has all the Tech2 features and capabilities. Including EVAP testing.