As far as I know all AdvanceTune devices are still vaporware. It's not even clear they are even working on this project. They claimed they would be using a later revision of the demod chip than present in the current Prof generation (7301, 7500, 8000). This has the potential of improving isolated cases of signal performance and more likely blindscanning, but I'll make a wild speculation these would be more incremental improvements than dramatic ones.
The Prof 7500 is a known solid performer, and unless you're willing to wait indefinitely, it's a bargain for what it can do today.