Lightroom and Photoshop, IMO are not comparable products...
LR is more of a cataloging/quick editing program, with photoshop being used for more in depth processes (any real degree of cloning, cutting out and various other processes)
What LR is is a very efficient batch processing tool, with a build in database of all of your images. Much quicker to do basic edits in than opening each image into PS (save batch processing).
One compliments the other