I have a very good 127mm refractor and C9.25 , similar in sizes to a 100mm frak and 200mm CAT and find while my refractor shows things with a little more ' Snap ' than the C9.25 in the beginning , but the C9.25 when fully cooled shows a lot more detail on the moon and planets .
Yes on an average night the 127mm shows a nicer image but I am afraid that even tho the SCT is not as sharp you do see more and thats what planetary observing is all about , eeking out detials .
Another plus for the SCT is that when I have finished looking at the planets ( we are very spoilt at the moment , but sadly it's not always like this ) deep sky is a whole lot more interesting , you can't beat physics as the 127mm is 50,677 sq mm and the C9.25 is a
whopping 173,433 sq mm ,
I am lucky to have both and you have to make a choice and if it was me I would get the C8 as its mounted already
, I assume the ED100 is not ? you dont say .
Brian.
ps . as you say a refractor is basically ready at a moments notice but the SCT needs cool down time , yes that's true and needs considering before going out , that's why my 127 gets plenty of air .