Not sure about the pot values. With EMG's, if you remove the tone pot from the circuit, you gain 3dB output, but they're not brighter. They're just louder.
You could try the 18 or 24V mod. That does give you a little more high-end, but also a little more low-end. Just don't expect it to be night and day difference.
You won't feel like they're hotter at all, just more dynamic. The peaks will reach higher because they won't be clipped by the preamp running out of headroom, but with the pickups clipping less internally, there will be less of a crunchy sound and more clean transients from the pickups themselves. The way EMG's work is at 9V, they actually distort a little themselves when you pick hard. You won't get that anymore. Or at least, to a much smaller degree.Does it also increase the output? That is not something I would want. Otherwise I'm going to try it. Don't mind if there is more bass too.