Only real reason is to get something smaller, the 7.8 is huge. The power on paper on the 7.8 looks awesome, however I know I don't need anything near that. The dac in the 40.7 is a huge upgrade, however I'm not 100% sure I would ever utilize it, even the dac in the 7.8 is probably wayy more sufficient than I need. The app control seems interesting. I don't have to do anything but was offered $240 for the 7.8 which puts me in this place. Basically the size would better suit my setup. any added benefits to the bigger dac, app control, streaming services, hi res audio? Open to other integrated or stereo amps as well. Was also looking at the emotiva ta-100.