I have both Lumendye and the Quantum X2D flash, which is the predecessor for the New Quantum 5D flash head model. (I will be buying a Quantun 5D flash soon, to complement my QFlash X2D model.)
My Lumedyne power pack, powers my Quantum X2D model. For power, capabilties and all the features, there's nothing to beat it on the market.
At my wedding last weekend, I did all the formals by bouncing the flash into the wall behind me. It produced beautiful shadowless bridal portraits inside a photo room. No LS, Flip It or diffuser could have done the same job! (I am a Canon shooter, so even the 580 flash couldn't equal the versatility of the Qflash models.)
There are 2 models of the QFlash. One that adapts to Lumedyne Power packs and the other to the Quantum Turbo Batteries. They are NOT interchangeable. The capacitor setups are different in the QFlash series.
Go the to Quantum site and check the info out. Choose widely, if you are interested. The only drawback is the cost!
Way more expensive than the normal flash units. But for sheer power, beautiful light, check it out!