FYI
Some experience
Extang Snap - no longer produced, throw back in time, maintain with 303 and will last, cover warranty 10 years and that is how long the cover lasts with minimal maintenance on the street. Have it on my 2001 still (2nd cover) and bought it for my 2019 while I tried to figure out the advantages and disadvantages of the various covers. Not for the highbrows and nose in the air type. Has served me well for 24+ years and it didn't leak in the 2001 Dodge Ram. Past due on ordering the 2nd replacement cover.
Lomax - good but need to take off and put somewhere if you need full bed access, easy enough to remove, nice profile.
Diamond Back - I guess as good as it gets for securing items in the bed. 1600 or 400 lbs. pounds on top of cover spread out, limits bed access, $$$$. Try to buy used, they are discounted pretty good usually, currently a 400 lb rated cover for $1100 on ebay on a 5' 7" bed. Love it in winter for cleaning off the snow, washing and waxing the roof. Bought it when I wanted to spend some of my 3 son's inheritance and leave my tools in the bed while in my driveway.
MX 4 - fills a lot of sweet spots, but rests on the back window. I avoid putting it against the window considering all the problems there are with leaking windows. Currently in use.
This should be read. Nod goes to ultra flex, although I prefer the finish on the Bak Flip MX4 but it doesn't rest on back window.
Between the Undercover Ultra Flex vs BakFlip MX4, the Ultra Flex is preferable. The reason is that it offers vehicle-friendly construction and fits completely
tonneaucoverguide.com
And this is a good looking roll up cover, seemed some commented on winter weather problems.
TruXedo Sentry CT Hard Roll-Up Tonneau Cover
You will find more info in the compilation thread. Try to figure your needs.
Best of luck in your decision.
Lucas Kylie at Truck Alterations was very informative 5 years ago when I was doing some homework, not sure of his current status.
