"reflex design is 4-5" shorter would make it ideal for home defense
applications"
Are you seriously considering using a AR for "home defense", in a situation where you may have to later defend your actions to a jury? I cannot conceive of a scenario requiring more than either a shotgun or pistol to defend my home. For no other reason than the realistic expectation that after the action is over, some prosecutor is gonna have my life for lunch, when I am prosecuted for "excessive force" or something similar. I'd consider a suppressor on my Beretta 9mm, with 147gr subsonic ammo for my own hearing protection, the "most extreme" for home defense. Of course, all this assumes I am defending against a robber/junkie trying to break in to a home in most populated areas. If I have a more remote home, with acres & acres of open, I'd opt for a shotgun with slugs. "My home is my castle" only goes so far, and shooting an intruder with any centerfire rifle so easily demonized by overzealous prosecution is "risky business" indeed. If you do live out in the country, you would be well hearing-protected with an AR with most any can like a SWR/Gemtech/American-manufacture, etc.
But again, the aspect of possible prosecution for the tool used to defend life and dependents is a very real factor to be considered. I would never consider my AR (and most especially not an MG!) as primary home defense weapon in any scenario that doesn't inclulde breakdown of major communications/commercial power such as the east-coast blackout.
my .02 worth, your opion of my opinion is your opinion!
for a efficient small package, the Warrior suppressor by Mike Klos is the best value for the money, in my book.