Is this limited to the Darbee 105 version, or is it common on the standard 103 and 105 as well?
The original 103 and 105 have a different video processor for their HDMI-1 output; it's the Marvell's Kyoto-G2H video processor (with the latest Qdeo technology).
* And this video processor is set with a very slight amount of softness (sharpness set into the minus territory) integrated into it (undefeatable).
And you cannot manually compensate for it by raising the sharpness control. And no firmware upgrade can fix it either. It is what it is.
The newer 103D and 105D use the new Darbee video processor (Visual Presence) with Darblet video Enhancer, for their HDMI-1 output.
And all these four BD players use the same MediaTek dual-core video processor for their HDMI-2 output.
<<<>>> No matter what, video accuracy is like audio accuracy; it is very rare indeed.
And the Darbee video processor is no different; it's a video enhancer (a sharpness/contrast control that operates in certain parts of the moving pictures) with plus/minus effect. ...Depending on its level setting, the source (cable or satellite TV boxes, Blu-ray, DVD, VHS, Laser Disc, ...), and the quality of the display itself (CRT, plasma, LCD LED, front projector, DLP rear projector, OLED, etc.). ...Plus the display's professional calibration or not.
Simply put it is a bit similar to like adding spikes to your loudspeakers, or upgrading a pair of interconnects, or the AC power chord, or some' of that sort in relating to the audio equation.
Works for some people more than others; the highest your picture definition is (resolution), the more noticeable the effect is (according to its inventor and the experts and most owners). If you have an OLED Ultra HD TV (4K), the Darbee video processing should shine even more.
...And of course you have comments that are all over the map because not two people have the same set of eyes and same display and same video control settings and same video setup and same all that jazz.
There is no absolute, just what yourself considers to be absolute. We always adopt and adapt to other's audio and video gear implementations, more or less.
And some people build their own video and audio gear themselves. ...For personal use, and also for business purpose.
And others buy licences from other developers. ...Like Oppo did just here with the Darbee.
But why am I telling you that Bud; I'm sure you knew that already, or most of it anyway.