Very good contrast. Usually no need for collimation. No diffraction spikes (well, SCT don't have that either).

In my experience, a decent refractor just does what it needs to do, without drama. There's no mirror to collimate, no mirror to flop. Once the imaging train is dialed in, you let it cool for a bit, you focus, you take pictures. It just works. I confess to missing a reflector's diffraction spikes, but the unobtrusiveness of a decent refractor is almost luxurious given everything that can go sideways with astro-imaging.

Agreed. I debated for a long time but went with refractors (StellarVue). The simplicity and quality are nice, and as you say it just works. I'll probably get a large reflector at some point, maybe, but refractors are great for simple high quality. Astrophotography is my primary interest.