Another tidbit from the Coelestis forum:
"pagai tanti anni fa un BAADER MAXBRIGHT da 2" quanto oggi si paga un dobson da 10", accessori compresi, sarà un ottimo diagonale, ma anche io non vedo la minima differenza con quello da 2" di serie e quindi gratis, sul MAK SW BD da 180/2700mm"
"many years ago I paid a 2" Baader Maxbright as much as you pay for a 10" dobson today, accessories included; it should be a great diagonal, but I also don't see the slightest difference with the 2" dotation, and thus free diagonal on the Sky-Watcher 180/2700 Maksutov"
Speaking of diagonals, when I restored a second-hand 60mm achro (SBS/Bresser brand), I compared its 1.25" mirror diagonal with my Celestron's 1.25" fully-multi-coated prism diagonal (made by Vixen). Both have been cleaned and flat-blackened at every place that's not optical. I shined a strong bulb on them from upclose, the prism gave a slightly brighter reflection, but maybe with a tiny bit of diffusion, that's hard to say cause the extra brightness could make it seem so.
The standard-coated mirror was a bit colder in tone, and a little bit dimmer since it does not benefit from the perfect reflection in the prism, but the reflection was very clean. Plus, its housing is all metal, whereas the Celestron has a plastic chassis with metal tubes and backplate. The plastic was not molded flat, surfaces undulated a bit and they were scratched after 20 years. Simply rubbing it on coarse sandpaper trued the flats, and chamfering the edges make it look like it's brushed aluminum now.
Trying them both on Jupiter, the Moon, some doubles and a few bright stars for intensity and diffraction testing, I could not see the slightest difference in brightness, contrast or sharpness. A 25mm Plössl, my Hyperions and my 7mm Nagler-clone Panorama were inserted in the diags in succession, no visible difference in actual use. The luminosity variance that the strong bulb made apparent disappeared in real use. Maybe the weak turbulence was enough to hide it, and a truly steady image would show it, but perfect seeing can't be had at will.
A standard-coated 1.25" mirror diag sells for 25€, and a multicoated Celestron 1.25" prism sells for 50€. That's understandable since the prism glass is more massive, has to be perfect within its mass, and needs three polished surfaces at exacting angles instead of only one, plus the multi-coating.
However the superexpensive Maxbright mirror not performing better than a "free" Sky-Watcher is not justifiable. It's often touted that stuff made in Europe has to cost more because it's better made, but if Europeans - my compatriots - are that smarter, they should be able to build quality for cheap.
TS 8x40 Wildlife, 10x50 Marine - Fujinon 16x70 - TS 80mm triplet, 6x30 finder, EQ-3 mount, TS 2" 99% diagonal - Celestron C5+ and 6x30 finder, DIY tripod - 5" Bahtinov - 12" GSO dob, 8x50 finder - Hyperion 24,13,10mm 68° - TS Expanse 17mm 70° - SW 7mm Panorama 82° - Ultima 2x barlow - Astronomik UHC-E filter - Baader O-III - Astro Solar 5" & 80mm filters - Sky Atlas 2000 - Rükl's Moon Atlas - Canon 400D - 5mW green laser