Although the Klais Organ gives a wonderful baroque sound, the amount of couplers and mixtures makes it a very versatile instrument indeed.
Here is my meager attempt at an improvisation to show it can make a convincing French/modern style instrument. The reeds aren't as loud and harsh as some of the French instruments.
Everything is coupled together and octave and sub-octave couplers are in use for certain manuals. The pedals run from 16 foot through 2 foot flues and 32 foot through 4 foot reeds. On the manuals all the mixtures are on, Great Trumpet is on (Great octave and sub-octave couplers are on). No other reeds are in use on the manuals.
It won't be everyone's cup of tea - I'm not even sure it's my cup of tea, and although an improvisation there are some fluffed notes!