I think it depends on the execution. For example, a well tuned dynamic driver, like those found in the IE800, IE80 or the IE8 are superb drivers (granted dynamic ones) and sound better than many dual BA models (or even triple). A dual driver UE5 is probably (I have never tried them) superior to the TF10. It comes down to tuning, configuration and execution.
Anyway, I have some bad news. The pricing and the entire product line of Flipears has changed. They have an upcoming single dynamic model which is set to replace the X model. The Aiden, a 2-way crossover design will replace the XXX as the 15k CIEM, with the Aisha, a 3-way crossover (unsure if that means 3 driver or not) model is now 20k. The new upcoming Aim is a Quad-driver (3-way cross) 23k. There is a possibility that the Aisha is a dual driver setup as they did mention that the Aim will be a quad, but did not say as much regarding the Aisha. The Aiden is definitely dual.
So there you have it. I'm gonna go for the Music One now as it makes less sense for me to hold out for their dynamic single driver model. The dual might be good, but I'd feel just a tad cheated paying triple money for a dual driver model. That and they don't take credit cards.