Not used that particular make and model, but as Rodger says, the floor has to level and smooth for them to work efficiently, and without locks on the wheels it will take at least two bodies to move your Land Cruiser should you wish to swing/pivot the car on one of the cars wheels
Hmm, just had a look at the item on Amazon, not enough feedback/star ratings for my liking, and made in China.
The wheels look like plastic and look a bit on the small side to me, 680kg lifting capacity each I think is a bit boastful, judging from the pictures.
At the end of the day, it depends what your going to use them for, and you only get what you pay for, personaly, I wouldn't buy them for my 100.
Good thing is, they are from Amazon so returning should be a breeze if you don't like them, just check out who pays for return postage, also I would do a Google search to see what other companies are selling them for, and what other have to say about them.
It's difficult to judge properly until you have hands on any item.
Good Luck.