For night photography, do long exposures work better or worse than taking a few photos and merging them in software (median blending / image stacking, like the excellent iOS app Cortex Camera)?
You can assume that the images are perfectly aligned -- assume the blending software corrects for both horizontal and vertical shifts and slight rotations. $2.99 iPhone apps do this, so it's not an unreasonable assumption. Alternatively, assume that a tripod + remote shutter release are being used, to eliminate movement between the photos. Long exposures use a tripod, of course.
So, does median blending result in better or worse image quality? Needless to say, assume other parameters (lens, aperture, ISO, camera...) are all the same.
(This is split from Can I merge multiple photos to reduce noise? but that question specifically assumes that I don't have a tripod, whereas this one allows for it. So they are different questions. I went through the links suggested there, but they didn't seem to clearly answer this question.)