USE CLAMPS to move them, these are HEAVY and will murder your grip. They are not EXACTLY 4 ft by 6 ft, just make sure you know that. They in will be off by a few sixteenths of an inch. If you don't want them to smell, buy them used. Oops, just kidding, they will still smell. But only a fraction of what they would be if you get them used... I bought mine used and kept them outside for over a year before putting them in my basement gym and guess what? The room still smells like rubber. Get used to it.
Gorilla tape the seams, too.
But will these be the cheapest and best value flooring you can possibly get for your home gym? 100%
Performance
Value
Build Quality