The Vetronix Tech 2 was the GM dealership tool from the mid 1990's til around 2010ish.
The reasonable quality Chinese knockoffs are sufficient to the task at hand. I own one with a case, CAN-DI and all of the adapters that cost around $350 shipped from Guangdong, China about 7 years ago. It's about $290 without a case.
The knockoffs are not without problems.
- I had to change the DC-DC Converter when it arrived requiring soldering skills and tools beyond a lot of folks skill set.
- Some of the super cheap versions have issues with the VCI module so you get to send it back or replace the VCI.
- I will not use any Tech 2 for ECM updates because any Tech 2 requires a fully RS232 compliant serial port on the PC doing the work. USB-RS232 will not cut it.
If you have a laptop or an old desktop PC that you can use in the shop the WiFI MDI clones are $200 and they work just fine over USB using Bosch MDI drivers. They're workable with hacked copies of Tech2WIN. GM-VXDIAG at around $140 is another choice again with hacked Tech2WIN and special drivers on the PC.
Tech2WIN is essentially a Tech 2 running on a PC using the MDI or VXDIAG as the interface.
The Launch PROS X431 Mini is around $800. It's from Launch Tech China not Launch Tech USA so you don't get support from Launch USA... Corporate and international politics I believe similar to buying a Malibu in Buffalo NY and not being able to get GM warranty in Toronto ONT... but it may be stolen tech by another Chinese company... the whole story ain't out there.
The Autel Maxdas DS808 is around $700 on sale right now. You won't find a better deal on a full function scanner that doesn't have intellectual property issues. Eric O uses these in his South Main Auto Youtube videos on customer cars.
One of the guys on the Impala Forums just bought a Vident iLink400 handheld that is supposed to do ABS Bleed among other bi-directional functions for around $160. He says it works but it's not super intuitive.
http://www.videnttech.com/product/item-79.html
https://www.amazon.com/VIDENT-Multi-...07FVMQ9TK?th=1
https://www.ebay.com/itm/322824891739?ul_noapp=true