I am in the process of deciding on some sort of PC based scanning/datalogging tool (i.e. DeltaDash,Scantool) but after much searching I have a few questions that have never seen addressed. I have read that DeltaDash is the most comprehensive tool because it reads the Subaru specific protocol as well as the ISO protocol from the ECU. The Subaru specific protocol is supposedly MUCH faster in transfering and accessing data, but I am not sure if that is much of a concern to me. Here are the main questions I have ...

1. Is DeltaDash the only tool that can read the Subaru specific protocol?
2. What iniformation would I be unable to access if I went with a ISO scanner like Alex's at www.obd-2.com?
3. Are the missing pieces of information from a generic ISO scanner actually accessable from the ECU but just not supported in current software? (i.e. extract them using custom software)

Any help is much appreciated!

Max