Second Telescope: Maksutov Cassegrain vs Refractor I bought my first telescope, a 3-inch refractor a few weeks ago. It has been a wonderful experience seeing the Moon, Jupiter, Saturn magnified and Andromeda, M33, M81 and much more for the first time.

Now I wish to get my second telescope. I was considering : 
Explore Scientific ED APO 102mm F/7
Bresser Maksutov Cassegrain 152mm F/12.5

I live in a high altitude region with Bortle 3 skies. I hope to see basic details on Jupiter, Saturn and Mars at high contrast and clarity and perhaps the disc of Neptune. Also occasionally deep sky objects. Portability and fast setup time are also a consideration. The MC is about 60% of the price of the APO. 

In addition to my 26 &amp; 12 mm Plossl eyepieces I plan on getting a 50mm Erfle (Field Stop 40mm) and a 6mm Plossl.

For mount, I was contemplating between Bresser Exos 2 and iOptron CEM25P.

I wish to know your experience with refractors and MCs, in general, or with these specific models. Since the MC is cheaper and has a bigger aperture, will the APO have any advantages eg.contrast? Also, what are your thoughts on the mounts?

Thank you for your answer!
I have viewed through many telescopes over the years and in doing so have met many people like yourself. To suggest a F/12.5 Maksutov will satisfy you would be the equivalent of telling someone to dive into the deep end of a swimming pool without knowing if that person can swim.

If it's bang for buck that motivated your question I think you would get the most if you just explore the capabilities of the 3 inch refractor for a while. There is a lot to be seen with that telescope and you have barely scratched the surface. 

Some prefer electronic eyepieces. Have you seen what they are capable of doing? I viewed with eyepieces for fifty years before trying a Mallincam ten years ago. I haven't used an eyepieces for serious viewing since. 

Take a look at the NightSkiesNetwork. It is a group that regularly broadcasts their observing sessions. 

https://www.nightskiesnetwork.ca/about

I cannot think of any better advice for someone like yourself than to stick your toe in the water for a few seconds before jumping in.