I have to agree with Astro_Bot.
I assume that when John talks "physics", he is referring to the large secondary of the SCT's that causes a loss of contrast and therefore slightly poorer view to an equivalent newt or refractor. This however would only be if the newt had an optimised (minimum size) secondary- and of course a top refractor will always "beat" (read: "have better contrast than") the equivalent size SCT, MCT or whatever because there are no restrictions on the optical path (assuming all other things are equal).
I have owned and used all of these types, and I have to say that my Celestron 800 CPC has excellent optics (as did my little MCT). I have never had problems with cool-down, and on a good night it has given terrific high-power planetary views, as well as very nice contrasty views of all types of nebulae.
- BTW, its optics improved considerably when I put a 2" GSO diagonal on it instead of the crappy 1 1/4 one that was supplied (why does Celestron do that?!).
If you put my SCT up against an equivalent, top quality, optimised 8" newt I suspect only very experienced eyes would tell the difference, and even then it would be only on nights of top viewing. (I also use a 4" Tak refractor and a good 12" Newt, so I am aware of the differences).
While the 130 is no doubt a very nice scope, it
will still be a quantum jump to a good quality 8" SCT which has more than double the light-gathering power.
A good quality 10" newt or above will be another jump, but you have to take into account portability, ease of set-up etc.
A very experienced friend has used an 8"LX90 for over 15 years, he has happily logged many 1000's of objects, taken it all over outback SA- and he has only just recently upgraded; to a 16" Suchting scope... I never heard any complaints from him about the optics of the SCT, and still don't even when he has the 16" to compare.
So back to Richard's original question: yes, a reasonable quality 8" SCT will an upgrade over the 130. But I would definitely go to a few star parties and look at a range of scopes before making the decision.
A great problem to have too!
All the best,
- Dean