Thanks for all the input! I decided to go with an 8" SCT. So much for going lighter and more portable, haha. In reality, though, it's only 3 lbs heavier than my current 6" scope. Maybe someday I will look into a nice Tak refractor.
This is a good choice, C8's are very popular for lots of great reasons. Lots of aperture in a small package. Long focal length so easy on eyepieces and great for small subjects that you want to magnify rapidly without exotic eyepieces. Small and portable and easier to mount than some 4" and 5" refractors! The mirror is still not super big so it doesn't take hours to reach thermal equilibrium.
Per your other comments, there's no magic in refractors, maks, newtonians relative to cassegrains when you're comparing aperture. There's minute differences, but a 150mm Mak does not compete with a 200mm SCT for example, Maks are not magical or special in some way, they're just another design. Aperture is aperture though. The only key minute difference is that an unobstructed optic will have the highest throughput of light and highest contrast (if well figured and corrected) for the aperture compared to a similar size aperture of a mirror design with folded light path and a second mirror (resulting in obstructed optics and the light throughput is reflected and it's not 99%, it's less, so you lose some light both to the obstruction and the mirrors themselves). A Mak is obstructed just like a SCT, the difference in obstruction size is small and not worth splitting hairs over. 150mm aperture for example will not "hold its own" against a 200mm aperture when comparing a Mak & Cassegrain. They're more similar than not. The only competition would be something like a 127mm refractor holding its own or besting a 150mm Mak or SCT, that is a more true comparison for the reasons mentioned above. But even refractor magic doesn't beat a much larger aperture (assuming well figured, well collimated, thermally acclimated). Lots of magic mystical things out there on tiny refractors and various designs people are just fond of. But at the end of the day, a larger aperture, well figured, collimated and thermally acclimated will simply do what those tiny instruments cannot do because of non-mystical physics and the instruments were built according to physics and not magic. You're set!
Next step is to get binoviewers if you don't already have them. C8 + binos + planets is just an incredible, compact, portable package for this (and no corrector needed on a SCT to come to focus so you can use the eyepieces at native focal length).
Larger aperture will win the day (assuming collimation is good, thermal acclimation is good, figure of optics are good at least in the center area), take a look at this (assuming you want to keep around 1mm exit pupil for brightness after magnification):
102mm aperture (4") 714mm focal length will hit 1mm exit pupil with 102x magnification
127mm aperture (5") 1500mm focal length will hit 1mm exit pupil with 125x magnification
150mm aperture (6") 1500mm focal length will hit 1mm exit pupil with 150x magnification
200mm aperture (8") 2000mm focal length will hit 1mm exit pupil with 200x magnification
Notice the relationship between magnification, exit pupil and aperture? So if you want to view something at higher magnification and maintain enough light (exit pupil) to see it, you need aperture.
Edited by MalVeauX, 31 July 2020 - 07:58 AM.