“I use them both, depending on what I’m doing determines which one I use.
If programming a module on 07 Hummer H2 and older vehicles I will use the Tech2 with TIS2000, if on newer vehicles I use the VCX Nano and TIS2WEB.
The Tech2 with the correct software can diagnose vehicles up to 2013 but only program up to 2007 using TIS2000.
I personally feel the Tech2 is a better option, I’ve had installation issues with the Nano but it has been working fine for a little while now.
I am using a small laptop with windows 7 with the Nano and the Tech2 for programming using Pass-thru mode and all is working fine.
If all you are wanting to do is diagnostics on vehicles then the Nano will do it and it will do everything the Tech2 will do. The Nano is an MDI 1 clone which is the tool that replaced the Tech2 originally. The Nano uses a windows based program that is a Tech2 emulator called TECH2WIN and has all the same menus and functions as the Tech2.
I purchased my nano gm along with a laptop with needed software from VXDiagshop, they use email support and Teamviewer if needed for a tech to login to your computer and look things over. they’ve been very fast to answer my questions and give support.
The catch with the newer GDS2 type is you still have to have a laptop and Tech2Win software and/or pay for a subscription from ACDelco Tech Connect to actually be able to use the GDS2 type of device while the traditional old style full Tech2 is fully independent for all diagnostics and testing functions. For flashing and software updates you can either pay for a short term subscription or get a copy of TIS2000 running on a computer to connect the Tech2 to (what I did).”