An interesting comparison. You can see some of the clear advantages of using a mono camera by comparing the uncorrected Vega spectra from the two cameras.
The continuum is smoother with the mono camera without the confusing dips produced by the overlap of the response of the three R,G, B colour filters
The colour camera spectrum shows fine scale ripples due to the uneven coverage of the different colour pixels. There are non sensitive pixels in each part of the spectrum; only half of the pixels in the green and only 1/4 of the pixels In the blue and red regions can detect any light. Because of this the camera is also overall less sensitive than a mono camera. (The effective pixel size is also larger for a colour camera, though in this case it is offset by the smaller pixels in the colour camera)
The greater sensitivity of the mono camera, the good size of sensor and the cooling would also make the ASI 174MM a good choice you decide to upgrade to a higher resolution spectrograph where exposures can be many tens of minutes or even an our or two