Saves time and much safer
I have been working on my own cars for decades, and looking back on some of those 'projects' i remember some sketchy points when using two jacks trying to seesaw the car up onto four jack stands and getting it high enough to work underneath.
Now, with QJ i just slide these under each side, line up the blocks and go.
Easily saves me about an hour of jockeying around with jacks and stands, and way more secure. Plus, with the wall-hangers, the whole kit takes up minimal room in my garage. Best purchase in a long time.