They aren't too low. Trying to put the buffer tube against your shoulder is why they are "too low." Cheek weld it up higher. It's not a magnum rifle, they used to sell a chin stock for these and you can shoot an AR with it against your chin anyway.
Chevron front post and express rear. Cut the close range aperture down to just wings and you get a clear sight picture with little in the way. A red dot will create a tunnel view if not mounted correctly and the longer ones make it worse.
One of those $40 green lasers off ebay is on my short list. It's Tueller distance engagement range, I don't have time to get it up to sight it. I need to place dot and pull trigger. When binary triggers get proven and cheaper it may get to the top of the list.
Don't forget Home Defense is about perimeter alarms, living the quiet life, not showing off your goodies to the public, having a hardened exterior on the home that can resist a 15 minute attack, etc. Last ditch guns, no so much. If someone can ring the doorbell and you open it, then what gun someone chooses is already too little to late and evidence of flawed tactical analysis.
Home Defense = they don't even try. I know, it's a gun forum, but Home Defense isn't about guns. It's about homes.