I currently own an AT130EDT refractor mounted on an iOptron CEM70. This setup performs very well as you can see in this image I recently took with a ZWO ASI533MC Pro: https://www.astrobin.com/45aeuu/. The mount performs flawlessly, and routinely guides between 0.3" and 0.6" RMS (using an OAG) depending on seeing, so all is good!
Next year, I think I will be ready for a longer focal length OTA to tackle smaller galaxies and nebulae. The only hard constraint that I have is that it must work with my existing mount, the iOptron CEM70, because I don't plan to get another mount for a long time. I am also planning to continue using my ZWO ASI533MC Pro, at least for some time, before eventually switching to something like an APS-C size mono sensor, in a few years...
I have been thinking about the Celestron 9.25" EdgeHD. It's a good value, and I can find plenty of reviews and lots of people have been successfully using it. But I am also looking at other options. For example, I wonder whether a GSO 10" RC truss OTA could be a good candidate. I like the fact that it is natively at F/8 and can be further reduced using the AP reducer down to F/5.4, i.e. a 1,340mm focal length. On the other hand, it has a much larger central obstruction, it has spider vanes, it is heavier and bigger, it is harder to collimate, etc. (the focuser will probably work just fine since my imaging setup is pretty light weight) Price wise, they are not too far apart (in the neighborhood of $2.5-$3K)
Let me know your thoughts. One thing that would likely keep me away from the RC is the lack of real reviews I could find. If you know of one, please share it Thanks!
Note: I am aware that whichever I end up going with, I will likely have to wait many months before receiving it due to everything being on back order, but that's completely fine with me.
Edited by jlecomte, 06 September 2021 - 06:29 PM.