But if DPP can only do Adobe RGB, how could you convert to ProPhoto (that extra gamut isn't there)
I am using ACR most of the time. Perhaps you misunderstood my posts: I was not favouring DPP but explaining the advantages and disadvantages.
DPP stores the adjustments in the raw file, that's enough for me not to use it except for "utility" purposes.
Regarding the auto adjustments, that means LR would counterbalance certain camera model's tendency for e.g. underexposure in a Pentax?
No, it has nothing to do with underexposure. It is rather a "unification" of the ISO setting. Many if not most camera's ISO values are off, for example ISO 100 should be called ISO 118, but the manufacturers don't want to acknowledge that.
Nevertheless, the automatic adjustment is a total nonsense; it can ruin the image. (and it is much more than what I listed above, for some cameras and ISOs).
The 40D is a particular case: @ ISO 100: 0 EV, @ ISO 125: +0.24 EV, @ ISO 160: -0.11 EV, @ ISO 200: +0.24 EV, @ ISO 250: +0.24 EV, @ ISO 320: -0.11 EV, etc.
These adjustments are for "compatibility": Adobe did not analyse the camera properly at the very beginning, the handling of the raw data was way off. I reported the error, and it has been corrected (the clipping levels were assumed incorrectly), but now the auto-exposure adjustment "makes up" for the previous error, i.e. the result is incorrect again.
But what do you say to that sharpness comparison at dpreview?
Is DPP really sharper, or could you go at this same sharpness level by going to the detail panel in LR? After all, it's non-destructive...
DPP is not "sharper". It does not sharpen too strong, and it should not. Anyway, the sharpening control of ACR is superior to DPP, for those, who want to get the final product from ACR. I am using it only for slight capture sharpening, the rest comes much later in PS.