I would say the independence of conductor length to voltage drop since current is measurable at any point in the wire is more important. another big advantage t

I would say the independence of conductor length to voltage drop since current is measurable at any point in the wire is more important. another big advantage to it is that it also is resistant to noise. (though you should be using grounded on on end TSP anyway) nowadays it's pretty common to use cat5 and read a bunch of things from the sensors though via various protocols. 4-20mA sure is a lot simpler to program against though.