One thing I've noticed is one metric of "better" that seems like it is going to be haunting us for a while: "stands out more" = "better".
I think this is a result of the perspective of being in a transition from "low detail unreleastic" rendering to adding more detail...by looking especially for detail, finding it more prominently becomes a measure of quality by standing out more visibly from "low detail unrealistic" rendering.
What I think this results in here is a phenomenon where emphasis of 3D effects, in still screenshots especially, strikes the viewer as being "better" over more realistic and subtle effects, and the interaction of the lighting and realistic limitations in the visibility of details in objects aren't considered subjectively.
...
Looking at the gaps in between the tiles, the DX 8 shot seems to suffer by an over-emphasis of black areas and rougher depth, giving the appearance of high ridges in the grout casting a large second shadow in some of the tile gaps. This also holds true on the tile surface, which starts to diverge from an appearance of typical tile due to the shininess being at odds with the deep pitting and distortions that goes with it (such that the shininess seems like it should have gone as well) due to the coarseness presented in the shadowing.
It does look unusual, but it doesn't look grossly unrealistic for the most part due to actual variance you can expect in real tile and grouting. Given that, the more emphasized shadows seem to satisfy a desire to find evidence of progress in graphical detail, unless attention is paid to the (fairly faint) unrealistic step transitions to "grey" that occur in the full screenshot.
The only major problem in the DX 8 tile surface is that it doesn't fit my recollection of the sounds and behavior of objects undergoing physics and friction with the tile...it fits the more subtle and smoother tile in my mind's eye, but not the more deeply pitted, and apparently thicker, one.
...
For the stone detail, I do think that extra detail is a successful fit for the surface, and that it could even be classified when taken by itself as "better" in the small size preview shot present in the thread before you click on it to follow it. However, looking at the shots at the increased size after following them, there is nasty artifacting and unrealistic "ghosting" around the details that isn't present in the DX 9 rendering.
In fact, from experience, I know the DX 9 shot, even with its less apparent detail in the shot, is detail rich while being, in my evaluation, more realistic (for the given surface detail resolution). This is because the detail isn't fully apparent in naked daylight illumination from above, but can be made more apparent by turning on the (more sophisticated of the two available) flashlight, and viewing the impact on the surface of its lighting.
The problem is that while such subtleties are more realistic (a pitted rock of fairly consistent coloration with such shallow and wide pits would tend to look less detailed in bright daylight, with details standing out when lighting is provided from a specific direction, plus it would have sand in the pits to make them more subtle), they are also less visible, noticeable, and convey a "lack of detail" until realistic circumstances bring the detail out (like cleaning out sand, changing flashlight position, etc).
...
What I wonder is when the evaluation will shift from looking for more universally evident detail (as I feel drove things like Far Cry's shiny pipes, the original HL2 roof video, and the details in the Source VST), to how realistically details are and are not made evident to the viewer? One thing I note is that subtle detail would benefit from higher resolution textures in magnification...is it too soon for Valve to (apparently) be trying this type of subtlety for some surfaces, or is it just that still screenshot evaluation is leading to an early verdict in the absence of the full atmosphere in which the surfaces occur?