Thanks guys for the comments...Dave I think you will be able to see the glow from the smile on my face a couple of hours away when the fort doors are done!
I would like to post a few better pictures of the finished framing to show the measures taken to prevent any sagging and will do so when I pull down the foam board that is protecting me from the elements right now. This will come down when I am ready to finally install the jamb and hang these heavy doors.
After carefully measuring and marking the panel, I begin cutting the 5/8" MDF to form the inside and outside of the 2 x 4 framework for each of four doors. I always make sure to only use one tape measure. I use a 5mm pencil to carefully mark my line and use incra measuring tools to finish my lines I mark for the Festool guide rail to line up with. I know this is very elementary for all here but using these to measure and mark helps keep the panel square.
Incidentally, I previosly worked out all my dimensions using Sketchup. I cannot stress it enough how valuable this program is for any project really but for me, one this large, it helps me work out problems before I begin cutting. It outputs nicely to a program called "Cutlist" as well so that in all your planning stages, and when you get good with the combination of these programs, you can eliminate a lot of clutter in your mind, freeing you up to concentrate on tasks at hand.
I use these for marking or as a square to extend tape measured marks.
Might I mention that THIS blade does not play well with the Hardi-Panel (yes Dave, cement board). I think this blade is shot but I may buy one of thos HF sharpening systems that has been mentioned here.
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=96687