Home studio is superior to Powertracks for both more advanced midi and audio multi-tracking, as it should be for the price difference, but also slightly more difficult to learn I would say. For the type of tasks discussed in this thread it is overkill unless you wish to use the more advanced features. Powertracks 8 is fine for stereo digital recording from the 7k and now supports DirectX real time effects for the final mix.

The audio quality with any of these programs will be no different to the audio quality of the software recorder supplied with the 7k. You just have many more features to manipulate the recorded audio, e.g. normalisation, cleaning up start and stop points, creating total silence between tracks or adding extra effects from the programs, so you pay for the extra functionality not sound quality. If you are happy with the built in effects of the 7k, you will hear no audio quality difference through usb recording to the supplied audio recorder, to powertracks, or to cakewalk, cubase or anything else.