I guess one of the lines of thought is that with something like the QHY600, you can always capture and full resolution and then bin it before working on anything. Or even just bin during capture if that is easier, it's what I would do with my Mewlon but that's when 2x2 binned gets me to 0.62"/pixel
With that though I'd have a 15mp BSI mono FF sensor with a QE peaking at near 90% and 7.52 micron pixels. Although it doesn't get the same SNR improvement with binning as a CCD it also doesn't have the high near noise which was the purpose of hardware binning anyway.