A few weeks ago I completed a new 11.5" build. I have 300-400 rounds through it so far and have made some adjustments along the way. The current and final set up are:

-SOLGW upper, lower, and M89 rail. I really like the M89. Its a tad bit chunkier than their M76 wedge lock. I like their uppers due to the tight/thermal fit with barrels.
-It started off with a Centurion 11.5" barrel. I have swapped it out to a Hodge 11.5". More on that later...basically looking for a little less gas when suppressed.
-FCD gas block. This is my first time using one of their gas blocks and I can't recommend them enough. I had to thermal fit this thing so it should have a tight seal with the barrel and gas port.
-Geissele SD-C trigger
-Hodge BCG
-A5 buffer setup. I have settled with an A5H2 and Vltor rifle spring. PMC Bronze 223 ammo was failing to lock the bolt back with the Sprinco Green unsuppressed.
-FCD ambi safety. I love these things. They are so smooth and crisp.
-DA flash hider and DA Sierra 5. My first suppressor and so far I really like it. POI shift was about 1.5" to the right at 100. That was with a non-magnified Eotech and terrible eyes. So take that with a grain of salt.
-Unity riser. My first time trying one and I am sold on the higher mount. I like the more upright position. I feel it is quicker for me to acquire the dot. It just seems to line up more naturally for me.

The rifle started out with a Centurion barrel. I started with an A5H2 buffer and Sprinco green. I made it all the way up to an A5H4 and the rifle was eating PMC bonze 223 with no issues unsuppressed. I took the bolt out to wipe it down and inspect it. The firing pin retainer was bent and had marks on it from the firing pin. So I took that as the rifle was still gassed a little too much. Enter the Hodge barrel with a smaller gas port. I had to back down to an A5H2 buffer with Vltor spring for PMC bronze 223 to be able to lock the bolt back unsuppressed.