[hatzie]

My Tech 2 really is only useful to 2010 or 2011 or so. The coverage is pretty well neutered past 2010. I still have some 1992-2010 GM trucks and that same vintage cars that I work on with my Tech 2. I still have a working Mastertech 3100 with the Tech 1A cartridges for the 87-91 GM vehicles.

The MDI should cover up to at least 2019 and probably 2021 for TDS service programming.
Service programming over SAE J2534 interfaces is different from bi-directional diagnostics. Autel charges a lot more for the J2534 box than a WiFi MDI will cost you.

If you want diagnostics you'll have to pony up for a GDS software subscription or get a hacked copy and a laptop that you will not dare connect to your main home network. I have a couple segregated VLANs on my router that can't communicate with one another but most folks don't have enterprise class networking equipment in their homes. I ran a hacked copy of GDS on my sitting duck laptop to see if I could then I bought an Autel tablet.

IMHO you're better off with an Autel Maxisys 906 or 908. You pay Autel now for a tool that doesn't expire and need not be connected to the mothership to verify your subscription. Eventually you may need to pay them a fair chunk of change (around $500-$700) for an update that still doesn't expire or you pay Delco more than the original Autel tool every year. There are several things I can do with my Autel that cannot be done with GDS or the VW VAS interface.