How about a very late reply? Sorry about that...

I've had the cover now for about 6 months and it is working great. Installing it is very easy, especially after the first time. It has been very solid and works great in securing my gear.

Some observations:
- A few parts associated with the locking mechanisms hang down below the top of the bed rails. Overall there is about 18" of clearance between the lower portions of the locking mechanism parts. I can still put my flush-height truck box in the bed, but it fits between two brackets from the cover.
- The system locks very well, but does rattle a bit while driving. The good news is I can't hear it unless I have the back window open.
- I get some leaks around the center section while driving that drip down onto the wheel well. There isn't enough weather stripping where the water runs off, so some is blown back into the bed. I picked up some additional weather stripping at the auto store which should do the trick.
- It has been in the mid-twenties the past week and the locking mechanisms still work great (they don't freeze). However, there was water between the cap and bed rails, so I had to use a pry-bar to open it once. Thankfully the unit is solid, so it popped right open.
- The SE model comes with four cleats for securing loads to the top. Unfortunately, they are the front and rear of the unit. I found the cleats online and have ordered two more to put in the middle section. That will allow me to secure gear at the front and still have the ability to open the rear lid.
- Installing the unit can be done with one person. The covers are more awkward than heavy. I can install or remove the cover in less than 30 minutes.
- The C-clamps for holding the unit on the bed require 20lbs of torque. I busted the bolt of one clamp the third time I installed it, so do yourself a favor and get a torque wrench. The good news is Diamondback sells the clamps for about $5, so I got a whole set of new clams (4) for less than $30 (including shipping). Got to love a company that doesn't scam you on spare parts.
- If I was to do it all over again, I'd probably get the HD unit. The SE unit is fine for what I'm using it for, but I'd like the extra capacity.
- The Line-X cover is worth the cost. I'm glad I don't have to worry about scratches or dents when I drop stuff on top of it. Even with the diamond plate surface, scratches and dents would annoy me. The Line-X makes the surface resistant to damage and helps "hide" it as well.

I'll try to post some pics of it in my garage soon.