If you're looking for a trem that models a vintage amplifier tone, this is not it. The Ghost was designed to modulate amplitude transparently and to keep your signal how you already like it. Optical isolation keeps noise at a minimum while providing a smooth response to the wave shapes you create yourself.
Trigger modes add an additional dimension by making it possible to create dynamic swells that are anything from a blip to minutes long.
Expression control can be assigned to depth or the speed of the wave. Controlling a blank preset (see mk3 manual) can also enable the effect to be used as an active volume pedal.
If your favourite tremolo or other modulation effect has CV or 0-5V expression control, you can use a Lightning Wave pedal to create new LFO shapes or keep it in time with a drum machine sync pulse.