I too own a PLR-16 and I agree with your assessment, Although at the range it provides good performance at 100 yds using the shoulder belt to steady the Pistol.
And the PLR is a good gun to use varmint hunting where you need a weapon thats easy to carry and lightweight.
I also use mine for scaring the Hell out of people, LOL
It is an awesome weapon and I am Happy I got it way before the Election.
AS to the .223, I shot a boat load of them in Nam and I don't have a problem with it's performance AT ALL, I also own an AK-47 and enjoy shooting it TOO!