I have a CM TM on my F350 srw. As function goes - I love it. Tools are handy, boxes are spacious and heavy built. I am in a dirty environment and surprisingly the hinges, latches, and hydraulic door cylinders have all held up well. I tow my gooseneck stick trailer (full nose front end) and my flatbed with no conflict at all. It is a very good bed for towing gooseneck and still having toolboxes.
I do have two complaints. The first is the fuel filler. Because of the size of the front box and the location of the fuel filler the hose that goes around the box it's very flat and I was unable to put fuel in the tank. I took it back to the installer twice but any fix was temporary. Eventually I drilled a 3 inch hole in the deck of the bed and just put the fuel filler out the top. Problem solved.
My second complaint, and biggest, is the finish. The powder coat finish was horrible and within a year I had rust bubbles coming up all over it. it's about four years old now and I've resigned myself it is going to look like crap.
When I buy another truck I will buy another bed this style because the function for me that big of a selling point. It works as advertised even if the finish is disappointing. That said, when I buy another one I will look for a manufacture if it will let me buy one primer and then paint it to match the pick up. I will not be interested in buying another one that has powder coated. I am not sure if C. M. still does it but they used to let you buy the primered.