However, the same skilled operator should be able to calibrate her minilab in order to obtain decent looking b&w prints on color-based paper (RA4 process - used by Noritsu & Fuji).
It's actually a fairly good way to test if your lab sucks ass. B/W is not forgiving to poorly calibrated equipment or chain stores that are cheaping out on replenishment.
small nitpick: RA-4 is a Kodak process. The Noritsu minilab I ran used Kodak chemicals. Fujitsu labs typically use a 'compatible' version of their own that can't be called RA-4. While the two systems work, we always found C-41 Fujifilm looked inferior printed on the Kodak processes and vice-versa.
The big problem with Frontiers was it was near impossible to fully eliminate the colour cast on B&W prints. You can kick the machine into B&W mode manually, but there are still limitations the RGB laser exposure engine and process puts on you. Practically that means you can't get a true black like you can with silver-halide processes.
They are still fabulous machines though. Awful user interface, but the technology behind them is pretty incredible.