On the subject of synching adjustments - auto-synching is quite sensible for batches of similar pictures. I do a lot of school photography and although I shoot individual portraits outdoors (therefore subtle changes in lighting across a time frame) I can usually synch settings across small batches of pictures. However it still surprises me how often I clone out a piece of snot around the nose of a three-year old, only to accidentally synch the same setting across another 20 pictures. The other surprising thing is that it takes me some time to realise the error until I notice a child has a slightly distorted nose or eye........
Jim
Oddly enough, for me, this is peculiar to Lr! I just did this. I made a local adjustment to slightly desaturate and brighten teeth and of course, the size, shape and position moves slightly from image to image.
I have done this in ACR for years and never had that problem. Mainly because of the difference in how images are handled. I'm hoping as I work more in Lr, I will get accustomed to the non standard nature of selections and how it handle them.
BTW, in Br/ACR you copy all the settings and then choose what to apply to each image. In Lr, it appears you choose what to copy and then it applies those to every image. The other major difference is in how "Previous" is handled. Because Br/ACR separate the viewing/selection and adjustment functions, merely selecting and viewing files does not change what the "previous" file was. Only when you go to ACR does it pick up a new "previous" and only if you actually apply the adjustments. If you cancel out, it still keeps the last accepted adjustments as "Previous". In Lr, it appears, merely viewing another image makes that the "Previous" image from which adjustments are copied.
Scenario: You have 10 images that are variations of a studio portrait. You select the first image and make adjustments. You then view the next 3 and decide to work the last of those(#4). In ACR, applying adjustments from "Previous", it applies the adjustments from image 1 (the previous image on which adjustments were made). In Lr, it applies the adjustments from image 3 (no adjustments). This is part of Lr trying to enforce it's expected workflow. It is assuming if you are going to develop, you intend to develop all images that you are viewing. That you have culled out all that are not going to be developed.
I won't say one is better than the other, just that it would be better over all if they worked the same way!
QUESTION: Is there a mechanism in Lr to filter images to only those that have custom crops or custom settings (or no custom crop or custom settings)? I don't see that in the filter bar, but was wondering if I can either put it there or execute that filtering in some other manner.