I'm with Moosedog, fyimo, and Rick A., keep it rock stock if you are not going to shoot it much or sell it. It's still a $900+ Colt AR as it sits, and a reliable, accurate rifle with good ammo. Modern AR's are the Barbie Dolls of rifles, you can dress them anyway you like. BUT, once you do a permanent modification then it's just another hacked up fence post in the eye of the buyer. Keep it stock or reconfigure with quality parts and accy's, but do no harm.
Disclaimer: I started out as a highpower competitor with a stock 1993-ish R6601 Sporter Match HBAR, then got into machine guns (including M16's), and then S&W. I've reconfigured and modified many AR/M16/M4's, but my original R6601 HBAR is still an iron sight 20" service rifle good for cleaning a 600 yard target with 77 grain Sierra BTHP over 24.5 grains of Reloader 15 (and just a little left wind hold). Just thinking about it get's me jazzed for some long range fun. Good times.

Disclaimer: I started out as a highpower competitor with a stock 1993-ish R6601 Sporter Match HBAR, then got into machine guns (including M16's), and then S&W. I've reconfigured and modified many AR/M16/M4's, but my original R6601 HBAR is still an iron sight 20" service rifle good for cleaning a 600 yard target with 77 grain Sierra BTHP over 24.5 grains of Reloader 15 (and just a little left wind hold). Just thinking about it get's me jazzed for some long range fun. Good times.
