First, thank you
@RickGrimes411 for a great write up!! and thanks
@sinner822 for the "all in one step" zips!! My experience as follows: was on Eclipse 4.0.2/NC5/Safestrap 3.72, did full wipe (factory reset), flashed GPE 4.4.3 ROM, then flashed sinner822's 4.4.3 all in one zip, then flashed SuperSU 2.0.1 zip, then reboot system. Success!! everything worked right at start up, LTE, WiFi, MMS, all good. Then........I went back to recovery and flashed GPE 4.4.4 Update zip (no wipe), then flashed sinner822's 4.4.4 all in one zip, then SuperSU again, then........almost success.......WiFi was broke, as in toggle greyed out and not available. First, tried NC5 modules zip, no go. Then tried gigilies NC5 wifi fix zip, no go. Then flashed the GPE 4.4.4 zip again, no go. Then, flashed sinner822's 4.4.3 all in one again on top of 4.4.4 and success!! WiFi is back!
Don't know what might be wrong w/ the 4.4.4 all in one zip but I'm all set up running Xposed and Gravitybox, no problem. Rom version says 4.4.3 in "about phone" but I know it's actually 4.4.4 (will look in build.prop and probably just change it there). Nice being back to Nexus feel on the GS4, phone is smooth and seems fast and stable!! Cheers!