I can't comment on HRT, but I tried salvation data myself. It is crap of crap. They tried immitation what PC3000 does, but were unsuccessful.
Why buying salvation data if you have pc3000?
Bus Analizers, etc... it becomes reverse engineering, and trust me, the companies that are not big, and that are not interested in developing data recovery tools - don't care about all that stuff. They need to make money recovering data, not to develop tools. I would understand that companies like ontack, etc... would buy these analizers for 20-30 thousand dollars and hire 20-30 software engineers to develop tools... but for smaller companies - why do they need all that stuff? I disagree with you.
Also - HRT - you don't really need it, as: 1) it's complicated for people who want to perform a quick data recovery. 2) pc3000 can do everything HRT does. 3) HRT does not support all drives.
My opinion - you need PC3000 and data extractor and that's it. Ohh, yes, you need a brain and straight hands.