We 2 railers are varied.
I have a dual system where my power source can be switched between DC and AC either the entire RR or just a portion of it. I am currently running PS-2 & PS-3 on conventional but just acquired a pair of TIUs to try DCS. I got two, One for the two rail and one for my three rail.
There is also a battery R/C which I got awhile ago so I could run something while under construction. I wish all my equipment was battery R/C.