A mono 2600 would give bigger real estate than a 294, no amp glow, 16bit versus 12 or 14bit but that's about it.
The 294 in the QHY version gives 2 readouts 48mp and 11.
I wonder how much difference there is in the real world between 14 and 16 bit cameras. All my CCD cameras are 16bit but then the actual image is always only in a relatively small slice of the available histogram slots.
Bit dept does matter a lot. Consider that all your data is in a tiny slice of the histogram. If you had an 8 bit camera you can effectively image 256 shades of color across the width of the histogram. If your image is in 1/10 of that histogram you're effectively getting 25 shades of color in the tiny area. That's not much. 14-bit color is 16,385 shades per color, and 16-bit is 65,536 shades per color. So in that 1/10 area, there is more color being captured.
This isn't however the whole picture. If you take very long subs, and very few total, you will have a lower bit dept. If you capture many dithered subs, you actually increase your bit-depth. Imagine that 1/10 slice of a fixed number of colors, is now offset from and layered on top of another image with that same set of fixed colors, when you overlay the two images and merge them together, you're creating more new shades of color, effectively increasing your bit dept. Do this over and over again with 100s of subs, and you can achieve 32bit color from 16bit images. Which is why PixInsight ends up creating 32-bit master images once you stack.