I have used weathertech digital liners in a LOT of my vehicles. I love them.
But, I do agree with one of the posts above about sometimes in certain vehicles they do move around. I find that if the vehicle has some kind of built in retainer for the factory mats they work great and stay put. But if they don't, weathertech gives you the little screw in retainer and I can never get it to work perfectly.
I added them to 01 Tahoe I just bought for my son and they move. I can't get the stupid screw in thing to stay put. I got the entire kit for that Tahoe. I also just bought an 07 for me and bought the front, second, and isle mat that goes between the second row captain chairs. The rear already had a cargo liner. They will not be delivered for a few days.
If they move too much and irritate me I will buy a set of the Lloyd Ultra carpeted mats. But they are carpet and if you are not really careful they can look bad like any other carpet mat. But man are they plush and look awesome.