OK, let's be honest here, we all know that by logic, NO obstruction SHOULD be better than ANY obstruction...
Now, in REAL-LIFE, the difference is NOT that striking...
Yes, there's a difference, but not something ABISMAL, something subtle, visible, but nothing that I would personally call "Shocking"...
Visually, my 10" SCT gives me awesome views (properly collimated - cooled), specially under the "almost always steady" Florida skies..., and even though I've looked through Refractors, and loved the views, I did not see something that would make me think about selling my SCT... not at all.
Also, lets make sure we understand that webcam imaging stacks hundreds, thousands of images, and the end results are a combination of these... not a very good way to compare image quality here, unless we had somebody that did this with an SCT or something else, and a refractor, side by side...
Clear skies!
Ivan