On Saturday, 4 June 2016 17:24:21 UTC-4, Sketcher wrote:
After 19 more days I will have had my 6-inch f/6.5 achromat for one full year. Last night - for the first time - I set up Excalibur (130mm f/6 apochromat) and The Beast (152mm f/6.5 achromat) side-by-side.

For the planets (Jupiter, Mars and Saturn) a Fringe-Killer filter was kept in The Beast. Not surprisingly, a few planetary details were better when The Beast was used at full aperture while most seemed better stopped down to 120mm. High contrast details (apparent sizes of Jupiter's moons and Cassini's Division) faired better at full aperture. Regardless, all planetary details (excepting only Jupiter's moons) were better with Excalibur.

I found myself often picking out details with Excalibur that I would later look for with The Beast - and usually I would be able to see them with The Beast, but it wasn't nearly as easy. Excalibur's images were 'cleaner'. Excalibur was the clear winner on planetary detail.

M5, a globular star cluster, showed significant resolution with both telescopes using a 6mm eyepiece. I picked out a faint star conveniently located between brighter stars for comparison purposes. The first test was between views in The Beast with and without the Fringe-Killer filter. I concluded that the view without the filter was better. The second test was between the two telescopes. I concluded that the globular test was too close to call. The Beast's extra light grasp was reasonably well balanced by Excalibur's tighter star images. I'll call this one a tie - at least on this particular night.

Next was NGC 6118. Once again, The Beast did better without the Fringe-Killer than with it. Both telescopes showed the galaxy as a distinct, faint-fuzzy at low and medium powers. The views were better at medium magnifications. The Beast's extra aperture was enough to provide better views. It wins the faint-fuzzy category - though a single galaxy may not be a very clear test.

Original plans, in addition to the above, called for targeting the Trifid Nebula followed by an attempt at sighting Pluto, but I was cold and tired. Tonight should provide even better conditions than last night; but plans haven't been finalized yet.

Sketcher,
To sketch is to see.

Good that you re-iterated the truism that (unless a telescope's optics are grossly poor) aperture wins over absolute optical refinement. I remember when there were people pretending a 130mm apo was a match for a good 200mm reflector and that was impossible owing to the sheer aperture advantage. Star images, etc., might be rudimentarily tighter in an apo, planetary detail might be more distinct, but it depends on seeing. However, you can't look at an unresolved extended object like a galaxy or nebula and beat a scope with three times the light-gathering area.