In practice and without testing I find my normal mugens roughly equivalent to my individual scuds. Certainly they are both better for me than the highly touted Japhods, which I rarely bother to use at all. I agree that the Scuds are probably best, but it's not particularly obvious to me in the real world.

One interesting thing is that the Mugens drop very quickly to zero and the scuds don't. When the Mugens get low I just get the warning three beeps at the end. With the Scuds I get the occasional one beep towards the end, then eventually I get the three beeps. In other words, the Mugens seem to die more abruptly.

Edit: Another difference is that the Mugens always start with 100 percent charge as measured by the advanced power monitor, whereas the Scuds never do. They are both charged with my unmodified external charger.