I got the emg-alx and put it and the booster in my rl600. It was a bitch because its solderless, but all the wires to the output jack are about 6 inches and the output jack on the wing is about a foot and a half away from the control cavity, so i ghettoly cut the wires to the output jack and twisted wires onto either end.
Previously I had just dropped the alx in for the h2. The alx was a little bit thinner on the top end and muddier than the h2, but had much better harmonics. Now with the mid booster it sounds quite a bit different. I'm also using a mxr eq before the preamp to boost 1khz to the max, but the resonance shift in the abx seems to alter the sound in a very different way than my eq pedal can. Setting resonance to the lowest frequency on the abx tends to give it a overly wah type hollow sound, while on the highest setting its overly thin. So the optimal for me anyways is somewhere in the middle, I haven't really figured out yet.
The booster seems to improve clarity a lot too, but sorta in the emg way, so I'm not sure how I feel about that.
If anyone wants to hear sound clips or whatever I can make a video, but I'm not sure how well my webcam mic would do.