I own it's smaller variant (a Sieg C3 7x14 resold by Homier) and it has no problem going thru aluminum. As long as you use sharp tooling, appropriate cutting fluid, and aren't taking ABom size cuts, steel is no problem either.
However...
That gives me pause...The owner tells me there is no problem at all, but refused to give me a demo before a cash deposit (for some strange reason I didn't understood nor asked lol),
Were it I selling the machine; I'd just stick some paper towels over the ways and have at it. Not being willing to do a simple, quick demo tells me that something is wrong: either the seller is hiding a problem with the machine; doesn't know how to calibrate it properly and thinks that a calibration error is a problem with the machine; or is seriously lazy.