I’ll be throwing this on a 16" bbl. I understand that the Battle Compe does a great job of controlling blast. I’m most concerned with muzzle rise and recoil reduction. Which is best?
It is my understanding that they are equally good at controlling muzzle rise, but the Battlecomp is not as loud to people next to you.
I’ve had both, now only have the Battlecomp.
The Battlecomp is the way to go.
To answer your question, I have shot both on a 16" midlength. They are about identical as far as reducing/controlling muzzle rise. The FSC556 offered noticeably more reduction in what recoil the AR15 has to offer. It allowed me to ‘get lazy’ with my stance and made it MUCH easier for me to shoot while moving laterally. I have shot both indoors and outdoors and the BC is quieter, though I personally do not find the FSC556 to be objectionably louder than the BC. I have equipped my 14.5" middy w/ an FSC556 and am blatantly biased toward the FSC. It’s my opinion that the FSC and BC are head-and-shoulders above most other comps out there (except for the 3-times-more-expensive KAC incolnel TT brake). There’s my $.02.
I would highly recommend shooting both if you get a chance…that’s the only way you’ll really be able to make up your mind about which YOU would prefer.
If that is all you care about, the BC still wins.
I have both. IMHO the BC is better at controlling muzzle rise and a LOT better controlling blast and noise. Since this picture, I’ve switched out the FSC556 for one of the “blems” I bought from BCE.
I like the BC 
I’ve owned both, and the Battlecomp 1.0/1.5 is superior IMHO.
thats good to hear since im ordering a BC.
I’ve have both - The BC now resides on my 11.5, 16" guns and the BC1.5 sits on a 14.5". The FSC556 sits on a loaner gun now.
Are you still supposed to avoid frangible ammo with the BC?
I believe they do recommend one jacketed frangible bullet.
NOTICE:
BattleComp tactical compensators are designed for Team CQB and are intended to be used with normal, solid ammunition.
Frangible ammuntion, very light plastic training ammo, paint-marking rounds and other non-standard ammunition should NOT be used with BattleComp products.
Frangible ammunition can come apart before exiting the barrel, which could result in a damaged BattleComp (jacketed MilSpec 62-grain frangible ammunition is acceptable). Lightweight marking rounds can easily become lodged in barrels for a number of reasons. Users choosing to use these rounds with BattleComp products assume all risk associated with such choices. NO ONE has ever been injured by using a BattleComp product, and we want to keep it that way.
To expand on what BWT posted the following quote is from page 50 of the BattleComp thread:
We recently ran a series of tests with jacketed frangible ammo and had no issues. Non-jacketed frangible ammo is not recommended for use with the BattleComp due to the round potentially coming apart as it leaves the barrel, a typical artifact of this sort of unsupported compressed metal ammo. Any standard jacketed ammo is fine.
Marty
For someone who is currently running an FSC556, would the advantages of the BC be enough to warrant a switch?
IMHO having run both, I would say yes.
I’ve personally ran at least 1200rds of 62gr Frangible ammo on two separate occasions, and notice zero damage to my BCE 1.5 on a 14.5in middy.
I replaced my FSC556 with a Battlecomp, so I would say yes. 
Pulled the 556 earlier this year… now have three BC’s (1.0 x1 and 1.5 x 2) and a 556 sitting in a bag… The Battlecomps are good stuff. No “Kool-aid” required.
Are the battlecomps quieter?