Pretty much this. They also increase backpressure on your already slightly overgassed barrel. Sometimes this is a good thing, like putting a noveske pig on a 13.7" mid but not a good idea on standard barrel lengths.
How about a super A2? A2 spec with 20% better muzzle rise compensation performance, and none of the extra flash, concussion and noise typically associated with a brake or comp, the 6315 
[video=youtube_share;D7VI2JFdbeE]https://youtu.be/D7VI2JFdbeE[/video]
Don’t include me in your “we’re all too maxxed” out statement. I don’t buy anything based on what it cost. I don’t buy too much cutting edge stuff either! TomMcC said it best…
I also don’t buy parts for guns because of how much they cost, but I care about function. A2s or Duffy’s A2 on the outmost from now on, for me.
Midwest Industries has an inexpensive two chambered brake. It works very well but the people on either side may get a bit tired of it.
No free lunch with a brake or comp. A hybrid device can mitigate flash, dampen muzzle rise, or reduce recoil. A pure brake or comp is fine for gaming guns, but for defense, both are terrible.
The fun part of our 6315, 6310 (5/8x24), 1815 and 1810 (5/8x24) project is to squeeze as much muzzle rise compensation out of an A2 sized muzzle device without incurring more concussion and noise.
1815 (and its .308 counterpart, the 1810) will be in production shortly, so we can now show the prototype. It’s an open ended, 3 prong flash suppressor, with asymmetrical ports (12 o’clock port is wider than the other two ports), and the two side facing ports are angled upward to vent gas up, not sideways, to help keep the muzzle flat.
Any concern with the top prongs splaying out like “I’ve heard” of happening with other three prong devices?
Material is 4140, heat treated and black nitride coated. If hit hard enough anything can bend. The bottom pic shows the upper 2 prongs as shorter, it’s not an optical illusion. There’s a slight 5 degree cant at the tip, the 6 o’clock portion sticks out slightly further than the two top prongs to have more gas vent upward, it happens to offer some protection. The thickness on these prongs are much thicker than the ones that peeled like a banana 
Is there an advantage to the open FH as oppposed to the closed type? Do they mitigate flash better or is there something else going on?
I’ve read elsewhere in regards to Surefire SOCOM mounts; 3prong > 4 prong > closed tine.
Surefire refuses to bring the 4p into the civvie market due to the fact that the 3p is superior. And the military keeps buying the 4p because it’s in the system already, and most of the time the mount has a suppressor, so the inferior flash hiding aspect doesn’t matter.
There’s some flash visible at the tip of the the A1/A2 slots, none with open ended designs.
We saw the same thing on the 6310 (5/8x24) as well.
Here’s a prototype 6310 (has been redesigned for better flash suppression) vs a longer factory AR10 flash suppressor on a 13.5" barrel.
We again see more flash in the flash suppressor body, and towards the end of the slots there was blooming.
Open ended and longer prongs do a better job than close ended and short flash suppressors.
I take it that the camera sees more than the eye concerning the pictures you posted. The flash would seem much smaller to our eyes in the field than these pictures show.
The flash happens so fast, the normal 30fps camera can miss the flash entirely sometimes, really need to use a high speed camera to capture more frames. We take side way pics, even though it’s not from the shooter’s vantage point, to better capture the flash, since from the shooter’s position, the flash from various devices all looks pretty similar, unless it’s really noticeable. If it appears a little brighter to the naked eye, it’s much brighter on camera.
In the 6310 tests, the flash signature looked identical to the shooter and bystanders. It’s only after we captured still frames from the footage did we realize they’re not the same. An M16/AR15 A2 has TDP dimensions and tolerances, not so much for the 308 “A2”, it’s an elongated version of the military A2. 6310 is a tad shorter than the Armalte Ar10 A2, the intermediate and secondary flash characteristics are quite different and that can’t solely be traced to the shorter length. The original 6310’s exit hole is larger and its cone shape quite different, which we believe caused the shape and size of flash to vary.