Why would I not want to Blend RGB and Text Colors Using Gamma 1.00?

Question

Shapes and text are anti-aliased visibly better with the blending settings in the Advanced Controls section of the Color Settings set as follows:
Just as an example, consider the appearance of the edges of this text and circular shape layer in an sRGB document with those settings set vs. cleared:
Set as above:
Cleared:
The difference is subtle, but significant in my opinion, marking the difference between okay quality and good quality.  You can see the difference in the partial pixel shading at the curved edges in this enlargement of a portion of the above:
So my question is this:
Is there any reason I wouldn't want to just set the above values and use them all the time?
I fully understand the concepts of gamma and pixel blending (and I think it's great that Photoshop has this feature), but I ask this question here because there may be subtleties of how Photoshop uses these settings I'm not aware of, and notably they are NOT set this way by default with Photoshop CS6.
-Noel

Answer 1

Chris Cox wrote:
You may need to change kerning or spacing to get them to hit different phases.
I've got several tests showing this, and the result is quite visible with Roman and Japanese glyhps.
Nope.  I can easily see the differences in a line of lower case L characters.  I don't know how well this will show for others, but here are screen grabs of the various settings.  Of course you'll have to look at these at full size.  On my well-calibrated sRGB monitor the gamma 1.0 text clearly has the least variation across the lines of characters in apparent brightness.
Gamma calibration and sharpness of the viewer's monitor will figure into how these look.
-Noel