Taking away the obvious, that a huge aperture will absolutely show more, especially on DSO that are already very faint, a refractor does the same job, smaller, wider FOV, lighter weight, faster to use, little to no thermal acclimation time, easier to mount, grab & go level stuff and it's fuss-free with no collimation. Mean while, a well corrected ED/APO can handle high magnification, so one can get a really wide FOV to a high magnified image in the same instrument, again, without crazy fussy collimation (a fast mirror system would be way fussy for this same act). I have a lot more refractors than reflectors/SCT, but there's no need to even attempt to convince someone that they'll see anything more in a 102mm refractor than they will in a 200mm reflector/SCT. They just won't. Now, there's of course the common story of a 102mm APO beating out larger mirrors on planets, but this is anecdotal and basically is just showing the difference between poor seeing conditions and thermal acclimation not being reached and then comparing them, as that's all that's happening there, the 102mm has no magic over a 200mm or larger, you're just seeing the poor seeing/thermal conditions more resolved and present on the larger aperture. Lots of that refractor-magic around here of course.
We love to use short and long refractors for quick views, fuss free, mostly to see planets and the moon and of course our local star.
We have larger aperture mirrors, so we use those for DSO. Seeing M42 in an 80mm compared to a 200mm is a very different experience, or larger even. My view of M42 from a dark sky where I live with 80mm shows a bat-wing looking shape, but from my 250mm mirror, it fills out and is a different DSO to see, I can only imagine how much more can be seeing from a 14~16" even or larger. Granted, the size/weight/usability of these big scopes really makes this a challenge for most people. But my point is that there's no refractor magic with DSO. They look good in the scope, but they do not generate magical light that wasn't there. If your preference for DSO is based on globs, clusters, stars in general, you'll love a refractor. But if your DSO preference is nebula & galaxies, a big aperture is the only way to really go if you want to see a bunch, literally a bunch more of it.
Even though we have big mirrors in our observatory, sometimes we just grab the 80mm, 120mm or 150mm refractors out and just use them for fun. Quick 5~10 minute sessions. No fuss. One of our favorite things about refractors is that they're fuss-free, no waiting, grab-and-go. If that means we look more often, but for shorter periods of time, then great! I will absolutely suggest a scope that is used more often, than one that will sit for months because it's too big or takes too much time to be ready to view with. This is where refractors usually win out for everyone, they're just so much faster to get out there with, setup, no fuss, no collimation, no waiting for thermal acclimation, and you can view a much wider range of FOV yet still push magnification too.
Imaging with a short, small refractor is much easier than a larger aperture, longer instrument. Regardless of what type it is. It comes down to the mount, the seeing, and thermal stability. The image scale on a wee refractor is so much courser and will handle poor seeing, and a less accurate stable mount. A larger aperture, finer image scale setup, will be subject to seeing conditions, thermal stability (focus drifting), and be a lot harder to mount, making it far more difficult to image with, without very, very heavy duty mounting and higher quality mount components in general. This is why a lot more people have their entry Chinese mount and a small refractor imaging and getting great results, compared to someone with a premium mount and a 14" RC in an observatory on a mountain. So again, no magic here, it's just easier to image with a short, small aperture instrument than it is a larger, longer one since it puts more stress on the mount being high quality and requires good seeing.