Dan,
I have used the old Revell rigging line myself on some of my models and I agree it still holds up pretty well. On my Catalan Ship build I purchased Syren’s line for the entire rigging and used it on other builds recently and I love it.
On my Dreadnought thread I plan on using EZ line like GM, although I might try fly fishing line on some of the WW2 ships when I get to them.
In regards to the CIM line, I know Rod Millard uses it and has been very happy with the results. He also stains his line to the colors he needs. You can see the line in use on his Catalan Ship thread here:
cs.finescale.com/…/160320.aspx
I also checked out Morope which is also very nice but unravels unless you glue the ends. I really do not think you could go wrong with any of these lines for rigging.
Steve