I would suggest that the KS8 (like the Rexton Adore) and KS9 (like Phonak Marvel) are about equal in technical aspects. There are some things that each does better than the other. They are from different manufacturers and the KS9 should not be considered as an evolution of the KS8.
The KS8 is MFi while the KS9 is not. However, the KS9 has a solution for both iPhones and Androids. The KS8 has a good program to adjust the quality of a streamed signal, mainly to boost the bass. It also has Own Voice Processing which allows it to identify the unique user’s voice out of all voices it “hears”. This lets it adjust the gain when the user is speaking. This in turn allows more closed fittings to be used, without causing an own voice problem. A second benefit is that it plugs into the 3D classifier, and allows the hearing aid auto program to adjust to 24 different listening situations. On the other hand the KS9 cell phone streaming method allows for hands free use of the phone. The KS8 is not really hands free. You have to hold it up to your mouth.
There are a few more differences, but I think they are both very credible aids.
Using a streaming cell phone is clearly the best way to hear when talking on the phone. The sound goes to both ears which gives you about a 3 dB gain in volume. Listening to a regular landline set as a speaker phone is not bad. The poorest is a regular land line held up to one hearing aid. That works, but is certainly not the greatest.
As far as needing steaming from a TV, I certainly have felt no need for that. But, that may depend on each individual’s “corrected” hearing level.
Hope that helps some,