I have for many years used the #3 FMP cover. Lots of room under the front flap for my Statler's and pencils. The back of it, there is a zip pocket, that held my mini-ruler, protractor w/measuring string, bridge-class aide-de memoire, etc. Inside, when I flipped it up, there was some important SOPs that were map-tacked under the upper "window" for easy reference, or key codewords, etc. The "mesh flap", if it is still the same design, was very handy as well. In the front "window" of that, I kept Tp level SOPs for quick reference. In the pocket of that flap, I kept my lens' for my mini-mag, to change off if/when, for some reason, the Tp color's were changed, or if I changed Tps in the field. I also tucked my copy of my Tp ADREPs in this part x 3 days, so if/when there was a question or "debat" with 49C as to what I had ADREPd, I could pull it out quickly, hand it to him before he told me to pound sand and get out of his $@#@#@ running re-sup.
I have seen some people (read Cpls on CLC/PLQ) go out and buy those JGs kits/case; and I said "not required, you aren't at Bde #@# HQ".
Yes, FMPs will rub you raw in the map pocket if you leave it there for a duration. I used to fold my map, to fit into my map pocket (in a zip lock bag of course) on my pants, and then put my FMP on the outside of the map. No chaffing. Later, I just added an extra utility pouch to my wedding for my FMP, map, Cutex, and triangle bandage. Worked great for me. When the crap hit the fan and I was in a rush, I just jammed the FMP and map down the front of my cmbt shirt, carried on, and sorted it out once we got the Tp moving.
Garrison? I had a FMP that I cut in half so it would fit into my combat shirt pocket. I found that "half FMP" WAY to small and narrow to be useful in an O Gp, in the dark, rain, and cold, trying to write fast with a Tp Ldr who had 5 minutes to give Tp orders and no time for my questions due to timings from higher.
For me, the "map against the leg in the map pocket, then FMP against the map" worked every time...
If you buy one, and don't like it...no biggy. Just get the one that works for you. I had the "economy model" one at first and found it didn't do what I needed it to, so when I found the one I was looking for, I gave the economy model one to one of the new guys in the Sqn that had SFA . You look after your troops too, whenever you can. It made his job as my JAFO easier, and he learned by "doing". Win win.
The other thing....once I had all my orders, CEOIs, at the time codes, etc in my FMP, during my O Gp to my Ptl, I could simply state "orders, codes, yadda yadda will be in my FMP in my FO or pocket"...my 2 i/c or crew would know where they were if they needed them. We trained that way....leaders at all ranks, die in combat. Someone has to take their place...quickly and effectively IMO.
"Train the way you fight, fight the way you train"
My 2 pennies.