Having the same issues with Lightroom 5.4. New built PC Asus Z87 Deluxe,CPU i7, 32g ram, Asus GTX760 video card. Photos on wd 2 tb 7200 hard drive, Lightroom resides on other drive.

Lightroom 5.4 takes a very long time to open catalog. disappointed. Plan to revert back to LR 5.3