I had LineX on my last truck. It was quite aggressive and decided to go with something a bit nicer on my knee's and things I put in the bed of my truck.
Went with the BedRug and TruXedo Lo Pro Cover ... Bought both from Chris at Freedom for just over $700 total for both.
The reason I went with the TruXedo Lo Pro over the more expensive Retrax was because I needed FULL access for full sheets of plywood.
Here are some pictures from the install today. Took a total of about 2.5 - 3 hrs total ~ This included the kids helping (or not so helping) clean the bed, and making sure everything was perfect. I could probably install both again in under 1.5 hrs ...