That's frustrating... You'd think Adobe would be able to show you the images as the camera made them like Photo Mechanic is displaying them
Hi,
I have developed certain strategies over the years to try to overcome this deficiency of LR...
First, I have developed a import preset in LR that tries to mimic the exact colors and other features of the embedded preview of PM (you will have to work out your own based on your camera, etc).
Second, I try to limit my use of LR just to the unavoidable, i.e. I only use it with pictures that need a considerable amount of editing. If I need to do just a little tweak, I use DPP (Canon's software) instead, because in it you can see the same preview as in Photo Mechanic (and you preserve the same fantastic colors you can see in your original photo).
HTH,
-Luiz Muzzi