[hatzie]

Un-translated data is the problem with the cheap ones. My guess is the Vident is similar.
Raw Mode 6 etc data is not good without the ability to interpret it. It's why I use Torque Pro for some of that.

My bet is they're being produced by the same Chinese factories that Bosch and HP were using when they ended support for the Tech 2. The only real bad thing about the decent gray market units is the power supplies available to us can't withstand a re-start cycle so they don't help diagnosing a tow-in no-start situation.
My Tech 2 wasn't that bad. I changed the power supply to a known pedigree DC-DC converter more because I didn't like the look of the unknown source converter that was installed in mine. Datel and Mornsun make decent trustworthy DC-DC bricks that fit the board and run at about 8vdc. The originals ran down to @5v IIRC.

If you have a few garage grade laptops available I'd think about going the Gray Market WiFi MDI route. The one I purchased in January is $229 with an SATA HDD with Tech2Win supposedly installed and working. I wouldn't connect to the internet with that drive but it's just fine for a garage PC with the network drivers removed or just never installed.

If you use the AC Delco TIS web applet to program a controller you can just use a different PC with a known pedigree OS along with the MDI.