Every scan tool I've seen offered to consumers only provides basic OBDII or CAN data. Some only offer the ability to view basic stored codes, and maybe a freeze-frame capability. This $20 scan tool from Amazon is a good example:
Most of these basic ones don't offer any options to view "live" OBDII data or graphs, and I haven't found any that offer the ability to view proprietary OEM data that would normally be view-able on a scan tool a technician would use, like this $10,000 tool from Snap-On (Verus Edge):
Clearly every gearhead would love to have one of these, but many of us don't have $5-15K to drop for one, let alone hundreds or thousands more on new software updates or personality keys.
These advanced scan tools give you visibility into thousands of more data points that can help you diagnose a problem, but with a universal scan tool, none of that is available to you. They're only really helpful if your check engine light is on, and even then, then they only give you a very limited idea of what's wrong in the form of a generic, stored CEL code.
Are there any affordable scan tools that come close to what one of those scan tools can do, that are available to the DIY-er? If not, why?