ok, a 7.5" pistol upper with an a2 flash hider is uncomfortable, in terms of burns, concussion, and noise. whats the best comp for directing the violence downrange, and making it the most comfortable to the shooter?

Flaming Pig!

Yea most will say the Flaming Pig. KAK makes a similar design for a lot less $$$$.  I also like the looks of the Troy Claymore but, haven't built with one...........yet.

I've used the BRT and Keneti-tech on a 300blk and they do the job. Same for a Levang on a 223. I like the lighter weight, lighter price models myself.

Spikes Tactical barking spider works great, my pistol is now a joy to shoot.

Check out this test of muzzle brakes. There is a part 1 and part 2 with new products tested. There are a ton of options, descriptions, data. Hopefully it helps you decide on which one you want. I am planning on trying out the Precision Armament’s M4-72 Severe-Duty Compensator. It's affordable and was the winner in both shootouts.

Part 1

Part 2

I have a flaming pig on my 7.5" piston gun and it works exceedingly well. I have a Spikes Barking Spider 2 on a 14.5" pinned/welded gun and there is zero flash or muzzle rise. Machine work on the Barking Spider is superb. I have seen the KAK cans and, while nice, they have a limited life span due to their aluminum construction.  The one I say was pitting, but it's under $40, so you can replace it cheaply.

Compensators typically have side slots, slots direct the sound and blast away from the muzzle 90 degrees, and that is a huge increase in concussion and noise to the shooter and those standing behind the muzzle. Which is why the military doesn't use them - teams stacked or working room clearing use silencers to keep from impacting their team mates.

The optimal pistol device is a linear - which throws all the noise and blast forward, which is the best we can do per ATF regs. BRT, Levang, KAK, Rousch,  Noveske, and a bunch of others are now available. The issue for a lot of us is price. The first four are under $50. They are mostly smaller lighter units. There seems to be a propensity to make the large heavy ones pricier, which for handling on a pistol doesn't work so well, much less with the budget. And the larger units don't slip under an overlength rail either, which is the current fad.

I have a BRT on my 6.8 and will likely use the fluted 5.56 on my pistol to finish it next month. KAK, nonetheless is very attractive, but even in aluminum weighs an ounce more. But, no matter what, a 7.5 is going to be louder than a 10.5, and there's very little to prevent it.

That is why I already have a device that will suppress all the weapons around me regardless, and which allows me to hear normally - a set of Peltor Pro Tac muffs. With a set of plugs, too, for shooting on the line or under a canopy. You can't have too much hearing protection.

7.5" 5.56 has a kak flash can
10.5" 5.56 has a levang
7.5" 7.62x39 has a kak also

7.5" 5.56 I use the flaming pig, works great.
10.5" 5.56 I use a YHM Phantom M2, works better.

how about this one?

http://www.midwayusa.com/product/524840/dpms-muzzle-brake-levang-linear-1-2-28-thread-ar-15-steel-matte

looks small, light, and best of all, cheap. anyone vouch for it?

The Kies Blast Master works very well on my 7.5" 5.56.

@skull.   . I have yet to see anyone with a KAK that has burned one up or even shows erosion.  Can u verify this or just hearsay?  That design does not create back pressure which means no gas cutting..    I have partners running this full auto on 556 for thousands of rounds and they look brand new inside and out

Ferfrans CQB Modular Muzzle Brake System if your hand guard is not too long or too small in diameter to quick attach/detach for range trips/conceal carry, etc. Big money, but it feels and fits like big quality too. I haven't fired my 7.5" without the CRD piece attached to the muzzle brake/mount, so can't make a comparison or a before and after effect.

I have this vortex style brake on my 7.5 pistol.  I've yet to see a big fireball out of it.  Works as advertised, cheap, and well made.  

Vortex brake

Kak flash can.

I have been using the KX3, but will be buying a KAK for my .300 upper.

Has anyone tried a be Meyers on a 7.5?

Have KIES Blast Master on my pistols. Massive improvement.

Here is what I use:  

http://damageindustriesllc.com/product/muzzle-projector-12-x-28-mk-i

Can't beat the price, and it works well to project the noise and blast downrange.

The term you want to search for is "linear compensator".  Direct that blast and flash down range...

Do you know what it weighs? I just ordered one because their so cheap but I'm curious as to the weight...

Not off-hand, but it is fairly lightweight.  

I don't have one off of a barrel, or I would weigh it for you.

No problem, I'll know in a week or so when mine shows up.

I know my KAK flash can weighs 4.15oz and my A2 weighs 2.1oz

What is securing the front end of that Magpul handguard?

I was wondering that myself.  looks great from that angle anyway.

I had to open up the handguard retainer to slide over the skinny part of the KX3. The retainer is reating against the KX3. It ends up being the perfect length.