The Extreme liner and Line-x ARE the same stuff, except for the Line-x ultra and I dont know what that is. Only difference is Line-x SHOULD be sprayed at about 125 to 140 mills thick on the bed floor and tailgate, dont go by the edges, everybody sprays them thick on purpose. Extreme is only recomending half the amount, around 60 to 80 mills thick, for hauling grocerys and golf clubs that is fine but for any hard use its not enough. Any Line-x dealer has a gauge to tell the thickness of any sprayed liner, (they have to because thickness measurements have to go along with the warranty registration) dont know if Extreme does or not. I'm a fan of Line-x since I sprayed it for 3 years but I wouldn't be afraid of a good sprayed Extreme either.

 

Another vote for Line-X as I have had over the rail on the last 2 trucks and have been very happy with it. When I was talking with one of the guys at the Line-X shop while they were prepping he mentioned all the different uses for Line-X besides a truck bed liner and was interesting. Apparently they will guarentee not to leak diesel when coated over concrete for like 48 hrs min. so a bunch of the local factories and hospitals have Line-X coating the floor and walls in the rooms for the backup diesel generators for enviromental reasons. Just a little tidbit of useless info.