I've got the Line-X. I found a good dealer who has been around for awhile. The installer has done over 2000 trucks, and did a beautiful job. The reason I went with the Line-X, is that they were the closest spray-in dealer close to my house that had the most qualified/competant installer/shop. There are some other shops, with off brand liners, but they were a bunch of kids. Always in a hurry and *****in about something. Good place for vent shades or running boards, not spray-in bedliners.
I would go with whoever has done the most installs and been in business for awhile. They all have warranties, and the products are all pretty close in the formula dept. , at least that is my take. I would talk with the guy doing the actual work, that is what sold me.
If you are in SE MI, Brighton Line-X did mine, $400
Mike