Damian's planetary work is absolutely phenomenal, but I think NASA's flyby missions and the Hubble had a slight advantage and edge.
You might have a better than average C9.25 and your seeing might be better than mine (on average). In addition, your eyes might prefer the brighter image afforded by the larger aperture scope (about 1.6- to 1.7-fold greater effective area compared to an AP155, correcting for the CO and scattering off the primary and secondary). Some days, that's the case for me. Other days, my eyes prefer views that are less bright, but have other good attributes. Example: the Moon and Mars often look better in my Zeiss 130 mm f/7.7 APQ compared to my AP155 f/7 EDF (to my eye, the blacks in the Zeiss are blacker). For my style of observing and location, aperture doesn't always win.
You don't need to convince me that SCTs are useful (although I have an AP 10" Mak-Cass and a Tak Mewlon 300, I can still see getting a cherry C-14 someday). The AP Mak-Cass is as good as others have noted. In addition to providing high quality views on the Moon and planets, I've used it to see the central star in M57 (directly overhead and at very high magnification ~ 950x both at home and more recently at the Black Forest Star Party).
LOL, yeah...comparing Damien's work with the NASA flyby's is an exaggeration; but some of his and other's work is getting awful close to what one would expect from some of the observatories.
I'd love to have one of those AP Mak's, or at least get to use one someday; haven't been around one yet to have the chance, but always wanted to try. I hear they're really good, even better than Mewlons. I'll bet you get some outstanding views from your scopes.
I'll agree with you on the higher contrast of the refractor, my 4" does quite nicely in that department too. That's one of the things that I really like about them. Even as a 4" I'm continually amazed how well it can find and pull in dim galaxies, and I attribute that to the contrast.
The more I think about it, you could have a point about people's preferences for contrast. I was out over the weekend on the Moon and Jupiter, with high shelf clouds moving through messing transparency up, while giving excellent P8 seeing. The slight decrease in contrast from the clouds actually boosted the detail I was seeing. On Jupiter the effect was like my scope had gone from a 4" to a 5" refractor with a polarizing filter. I remember that same thing back in '09 on Mars. For the Moon & planets, it seems the decrease in contrast can help to bring out detail. Other times, I want all the contrast I can get and an SCT doesn't do well on that IMO - that was my one complaint with the 9.25, that it didn't do as well visually on DSO's as I'd hoped. Up to that point I'd owned newts for about 20 years.
BTW - the 4" is all I currently own, hoping to either find the room here for another dob. If not, then I'll pickup a C8 or 9.25 to ride on my CG-5, though I have been considering a C6R or ES-150 OTA for DSO work. So I hope I've been able to keep my comments unbiased, since I really don't tie myself down to one type of scope.
Anyway, best to you here, I'm out for a while, maybe the whole night.