The original question by Eggzactaly:
Other than portability/convenience(?), what other reasons are there for going with a refractor vs reflector in terms of visual observations?
A response by Starman1:
--due to light pollution, they ONY observe Moon and planets
--they want to pick up the scope and mount in one piece and move it outside.
--they use the scope for photography AND visual observing.
--they want something that comes to thermal equilibrium very fast.
Addressing the above: I don't only observe brighter objects. My larger refractors cannot be picked up and carried out (scope, mount and tripod) in one piece. I don't use any of my scopes for photography. I do enjoy the benefits of quick cool-downs; but my 5-inch oiled apochromat actually does need some care when being taken out (and being brought back inside) in some of the temperatures than can be encountered in Montana winters.
As a visual observer who prefers using refractors, I can try to put into words my reasons. Note that I'm not writing about why "they" (other people) prefer to use refractors. I'm writing about why I prefer using refractors:
First off, I've lived and observed under some of the darkest skies for the past 40 years or so. And yes, I do enjoy observing the moon and planets. But I consider myself to be primarily a deep-sky observer. It's not unusual for me to see more with a small refractor than many can see when using larger reflectors. The first sketch below was made when observing with an itty-bitty one-inch aperture:
And the second was made with a 5-inch refractor -- (without the use of any filters):
Note that B33 is the Horsehead Nebula -- often a challenging visual object for many using telescopes of more than double that 5-inch aperture. Also shown are IC 434 and NGC 2023.
My 6-inch and smaller refractors, under my skies, can show me far more than enough to keep me busy (and content, and very happy) for the rest of my life.
Consider that a 1-inch aperture can show this much on our moon:
My larger refractors can clearly show far more detail than I could ever document. I don't need larger than the (6-inch and smaller) refractors I currently use.
What is it about refractors for me?
It's not something that's easily pinned down. Ease of use is a factor; but I use to have one of my larger Newtonians housed in a roll-off roof observatory. That was pretty easy to use as well -- always at ambient temperature, always in pefect collimation. But it was big -- bigger than necessary for my purposes. I don't need larger apertures. I don't crave larger apertures. I no longer even enjoy looking through larger aperture telescopes. Yet, if I change my mind, I still have a couple of larger (than my refractors) reflecting telescopes that I could use -- if I decide I want to use them.
I can comfortably sit on my observing chair, with both feet on the ground, and do my observing and sketching while using my refractors. The refractors are easy to take outside, setup, use, break down, and bring back inside.
There's just something about using an unobstructed aperture that's different -- better. I enjoy the wider true fields of view offered by my shorter focal-length refractors. Yet, they're also usable at much higher magnifications as well -- a Jack of all trades.
Refractors are easier to care for. Refractors are easier to safely clean. The sealed tubes keep insects, spiders, dust, etc. out of the optical tube assemblies.
I enjoy using the (strictly manual for me) GEM mounts that go out with my refractors.
My larger refractors can handle all the magnification I care to use when it comes to planetary observing.
So, for me, part of the reason is the darkness of my skies -- at least when it comes to the deep-sky aspects of my observing. Another part is me and my attitude toward visual observation. It doesn't take much to satisfy me. I care about seeing all that I can see, regardless of the telescope I'm using. I'm not so interested in seeing more. Seeing enough is good enough for me. And my refractors can handily show me "enough".