I do legitimately own Ballblazer and a (long-since dead) 7800. That's how I know Prosystem/Wii7800 are failing to play all of the music - Ballblazer was easily my favorite 7800 game when growing up.
If I were to re-acquire the old hardware, I would likely either be burdened with having to use the original RF video output, or finding someone to mod the machine to accommodate composite video. (unless I had the good fortune to purchase a pre-modded system.)
Furthermore, it would require more space around the already-crowded TV, and a further set of wired, unwieldy controllers to be kept handy. While there is a certain thrill to be had in using the original hardware, emulation is much more convenient and less stressful on the wrists.
Just seems odd that the two emulators, being both open-sourced, haven't taken a peek at each other to correct their own deficiencies.