Completely agree with you. Have used Autel and is the cheapest scanner that provides dealer level troubleshooting capabilities. It can be expensive for car owners though.I posted a complete write-up on scanners vs code readers about a yr ago..
Autel has a couple of commercial/professional scanners comparable to snap-on, for 1/5 of the cost..
If you are into real diagnosis, a DSO is in your future..
There are a couple of other scanners that can be found on Amazon for under $200 that are able to read and erase transmission, abs, and airbag codes on top of the ECU.
This is a great article for anyone who is looking to invest on a OBD II scanner. Best OBD2 scanners Hyundai Kia – Top Hyundai GDS Alternatives
The Autel scanner that Philip mentioned is in that list as well.