This may be a repeat. I sent a reply but it has gotten lost somewhere.
I have used Fotospeed and Nelson's Gold.
What are you trying to achieve would be my first question? For archival only I would use the Fotospeed as it is pretty much a typical standard gold toner. It does cool and will shift to a stronger blue with time and paper change.
Nelson's Gold is part of the Sepia class of toners altho, it is warmer . Runs to brown rather than yellow. THe results are better when used at 110 to 120 degrees. Paper type also effects the results. Warm tone paper shifts greatly. It is also best to use a fixer with hardner after toning.
Some of the older papers did wonderful things with this toner. Very interesting and dramatic splits would occur. Yet to have this happen with the newer version of papers.
Have not tried to 231.