The following shot has been processed in both for comparison purposes. It has been heavily cropped from a Canon G10 image taken last week.
This shows that with some practice it is easy to replicate in LR4 a LR3 processed image.
In this example (another G10 shot) LR4 handled the highlights much better while preserving greater detail in the shadow areas of the wooden carving.
So far I like the way it handles images and I hope Adobe can address the speed issue in the final release.