hey Bill
I was the one that started the thread, and had the same questions. I took the trip to Reno like I mentioned, and it was well worth it. Here's my thoughts, since I went there looking with the same questions in mind.
The weight is distributed on all 4 edges, all the way around. My shortbed shell will run 375 lbs with 3 racks on top. The racks will be built to your spec. I have an over-the-rail line-X. The shell will work perfect that way. My plan on the interior floor is to build a two-piece removeable floor with a padded durable carpet for comfort and insulation, but removeable and reversible for heavier use and occasional cleaning. I don't know how the bedrug fits, but the frame of the shell drops down to the bed, and across the floor in the bed along the tailgate line, which adds to it's overall strength and integity, so if you get a bedrug, it will have to be trimmed that 1". I couldn't imagine that being a problem, but that's it.
I was completely satisfied with the quality of this shell, and I looked at it with a very critical eye. The workmanship actually exceeded what I was hoping for. The one thing I'll do when I get it, is machine a bronze sleeve and replacement shaft (and a spare while I'm at it), to tighten the feel of the door handle. It's not that it's weak or anything, I just want it to feel and move like a safe's handle, and it will wear better over it's life.
I talked a few hours with one of the owners, and they have good reasons for pretty much every detail of construction they use, and based on the answers of my questions, they're a real sraight-forward outfit to deal with. What I found out, it was the same company my grandfather bought his shell from in '73. He ran with that shell for 25 years of retired travelling from SoCal up to Victoria,B. C every year with a 16 foot boat on top, and 6-8 trips a year down to baja in the fall/winter/spring time. His held up great with no problems, but I will say it was butt-ugly... but that might of been because it was on a ford. The new ones with the contoured front and tapered sides fit well.
When I flew to look at it, I got in at 11 pm & flew out at 2pm the next day. I don't do much spontaneously, and promised myself not to buy when I was there. I mailed in the order 2 days after I got home. There is a 3 month lead time, and I'm due to drive up there to pick it up the latter part of May. Hope this helps your decision.
sarj