or Brian ;-)

The thing with idex is not that you can use 2 materials, but more that you can use 2 completely different meterials with different print speeds and temperatures.
So you could have one head hooked up to tpu, nylon, polycarbonate, soluble material etc and the other to a squillion different colours of pla.

With a one nozzle multi material machine you'll always either be waiting for the nozzle to heat up or cool down. Just inefficient.

And yeah fascinated to see just what kind of speeds you can get from Brian :-)