I really don't see a problem with ACR's exposure bias adjustment. It is nothing more than an offset between the actual exposure value and the displayed exposure value. Under no circumstances does it cause unrecoverable clipping. If the exposure bias is +.5 stops, then the actual exposure adjustment is +.5 stop when the displayed exposure adjustment is 0. If you have a perfect ETTR shot, sometimes you'll see clipping when the exposure slider shows and adjustment of zero, but in all cases, moving the slider to -.5 will eliminate the clipping. There is no case where the exposure bias adjustment will unrecoverably clip channels in a RAW image. All you need to do is move the exposure slider to the offsetting value, and the "issue" is completely eliminated.

Jonathan, yes, that's fine. But to remind about the main point of this discussion, starting from the OP, it's about the predictability of getting a good ETTR: <<do you develop a feel for how much to expose to the right, getting non-clipped shots most of the time?>> In this context, ideally one would want a set of defaults for both the in-camera JPEG and ACR which start by giving a reasonably reliable read of how the camera histogram portrays the raw data, and then in ACR, hoiw its histogram portrays the same data. The idea - and ideal - is to operate in both stages with as little custom adjustment as possible after say the second capture, once the first histogram is available - or even the first capture if we're talking live-view with live histogram. In this regard, the comments by Andrew on the camera's JPEG settings, and by Eric, Bill and yourself on raw file programs for evaluating the raw data apart from Camera Raw have been very helpful. I think the answer to the OP is that one needs to work with these tools and experiment till one finds the settings that work best for various kinds of imaging conditions.