Well, since I have refractors and I also have Newtonians; and since I choose to use my refractors far more often than I choose to use my Newtonians, I suppose I should make a contribution to this thread:
It's not easy to pin down why I prefer using my refractors. The simple (and rather meaningless) answer is: "Personal Preference." But the likely followup would be: "Why?"
Well, it's easier for me to take my refractors outside and to bring them back inside. So that may be a part of the situation. On the other hand, back when I kept one of the Newtonians in a roll-off-roof observatory, the Newtonian tended to get used more often. On the other hand (It's OK, I have two hands ) I switched to my current refractor preference a few years prior to removing the Newtonian from the ROR observatory. So . . .
I don't care much about being able to resolve closer doubles or to see smaller and fainter DSOs. I can resolve "close enough" doubles and still see plenty of small, faint galaxies, etc. without having to use one of my Newtonians. It doesn't matter to me if they're not the same doubles nor the same DSOs. Similarly, I can see plenty of detailed, structured DSOs with either class of telescope. So, I might as well choose one and enjoy all that I can see with it.
So why does my choice always end up being a refractor? Hmmm . . . Well, it's easier, more intuitive, for me to point a refractor at an object (before looking through a finder) by sighting along the OTA. After all, the eye is nearly always near the back of the OTA. So that probably contributes to my preference.
What about planetary observation? Well, from my location it would be a rare night that I would be able to use a magnification with one of my Newtonians that would not be practical for use with one of my refractors. So, either telescope will work for planetary observation. Besides, I'm not into this hobby to always see more. I'm happy to see as much as I can when using whatever telescope I might choose to use.
That last sentence might the key for me. The telescope and the level of detail, light-grasp, etc. are not that important to me. I just want to make observations. So what if someone else can see more with their 92-inch telescope? That doesn't matter to me. All that matters is what I can see with the telescope I'm using.
Am I making any progress here?
It's easier for me (during takeout, use, bring-in, and storage) to keep my refractor optics clean than it is to keep my Newtonian optics clean. It's also easier to safely clean my refractor optics (if they were to ever need it!) So this might be a factor in my preference.
I do prefer my generally "cleaner-looking" refractor views. Yes, I have some CA with some (but not with all) of my refractors; but my Newtonians collect more light, so any light scatter (more of an issue with mirror optics) and diffraction effects are going to be more obvious to the eye when using a Newtonian. I simply prefer my refractor views -- personal preference (again).
So it looks like, for me, the preference (for the refractor) tends to be related to:
a) easier to take out and bring in
b) easier to keep clean and to safely clean
c) easier to direct toward targets of observation
d) cleaner views
e) My refractors show enough to satisfy my needs.
f) The usual Newtonian advantages are of no importance to me.
g) (not mentioned above) Cool down times for large mirrors -- not an issue.
h) Oh, and I needn't check/adjust collimation
I'm sure there are other reasons that just aren't coming to mind right now.
But more seriously, for me, it's really just a matter of my own, personal, preference. I gain more pleasure out of using my refractors. And that's really the only reason that matters.