Correct, and they're also known for their less-than-stellar performance. I have a '76 R90/6 with the under-the-tank MC, and one of the future mods I plan to do to that bike is convert to a handlebar-mounted MC. The bike just does not stop very well and, by all accounts I've read, it's because of the cable-driven MC.
So I'd look at going with a small MC perhaps, or maybe one with a remotely mounted reservoir like the one shown above, rather than a cable-driven one.