I've just given it a hammering today and while I'd love to love it, DT is not going to give the LR team sleepless nights. It feels quick, but the interface lacks the silky refinement and there's a lack of coherence in the workflow. Plus the correction effects work poorly, such as shadow correction which affects regions outside shadows in one direction, not all shadows in another. The workflow coherence is based on the old Adobe RAW flow, which meant that all controls were to be applied from the top down in the order, starting with white balance and moving down. That coherence was diluted somewhat in newer versions of LR, but it is still good.

I too am shackled to OS X by LR, but I am a very demanding, heavy user of LR.