Williaty, which laptop-based program are you using, and how do you like it for cost vs. performance?
I'm using a collection of free open source programs that are specific to recent-model Subarus. A program called LearningView allows me to pull DTCs as well as view the contents of the ECU RAM (fuel trims, learned timing advance/retard, etc). A program called ECUFlash allows me to pull the ROM from the ECU, modify nearly all the parameters, and then write the modified ROM back to the ECU (aka "tune it"). A program called RomRaider allows me to log a BUNCH of parameters (basically all the OBD-II parameters, all the Subaru Select Monitors (aka the dealer special scan tool), and a whole bunch of stuff not even dealer techs have access to), log the data to disk, view the numeric values in real time on-screen, view the parameters as a graph in real time, has a built-in tool for dialing in the MAF scaling, a built in tool for dialing in injector scaling and latency, and a built in software dyno. All of this runs off a OBD-II/CAN to USB cable. The one to support the CAN cars is $170. One that'll support the non-CAN cars only is just $13 on eBay.
It's an absolutely FANTASTIC solution... for the limited range of cars (about 100 year, model, and trim level combinations). If the ECU you're trying to talk to isn't on the supported list, you get jack.
Hence needing the CReader V to talk to older cars.