So you have one AR in 5.56, built another one in 9mm for a little over $600-smackers and you want to know if you should dump it for an Aimpoint? It only took me one millisecond to think of an answer…
It’s been said that two guns are one and one gun is none, hence the need for a backup. Right now you have a serviceable carbine with a BUIS. I would keep your second 9mm AR since the 9mm is cheaper to shoot, makes a good trainer due to the lighter muzzle blast and cheaper ammo, and as mentioned earlier, some ranges will allow you to shoot 9mm but not 5.56mm. If you want an aimpoint but can’t afford it right now, just do like I did when I built my son’s rifle, just take $50 out of each paycheck and in no time you’ll have enough money saved up to buy the aimpoint outright as well as keeping your 9mm AR.
I agree. I’ve kicked around the notion of building one of these trinketts several times over the years. Everytime I get into the details, I back away. It’s just not right.