It won't have the scream that the JB has, but it should have the warmth and power that the Custom has. The resonant peak is the point on a frequency response graph where the pickup is the strongest. On all the typical humbuckers its between 5-7khz but on the Trembuckers it's lower. That can be deceiving because pickups have secondary peaks, and it doesn't show "how much" higher the peak is than the rest of the response. You can have a high and lonesome "mountain" peak around 5khz on one pickup, and it will sound brighter than one that peaks at 6.5khz but in sort of a mild hill shape. The lower peak on the Trembuckers is exactly what floyd guitars are needing, though. Acoustically a floyd style
trem guitar will have more 6-7khz than the same guitar with a hardtail or
strat trem, and less 3-5khz. I think you'll really like it.