long as your happy with it, that's what counts. as you said most mass produced rifles, including the military ones, come with cheap furniture. with that said it works just fine. When I got my first AR, I decided to keep it as it and shoot it. See what I felt needed changing. I ended up with a magpul CTR stock, because I hated the rattle and slop. A magpul MOE grip because the factory grip was too skinny and I did not like the finger groove. The mil-spec handguard was too chunky. I like the MOE slime line, its better. An i have a free float on one gun. the plastic handguards do better with heat than the free float rail. the free float feels a LOT more secure. I ran the bird cage. it was fine, minimal muzzle flip. I tried a couple brakes and flash brake combos they seemed fine. My buddy got a kaw valley linear comp and we got to shoot them side by side. it significantly reduces blast both compared to a comp and a flash hider. Its hard to tell shooting at different times. but shooting side by side its very noticeable. I put jp rifles enhanced reliability spring kits in a couple guns. trigger was much improves, 100% reliable. I put a larue MBT in another. amazing trigger for $80. I hate the heavy gritty mil spec triggers. added optics and things have really not changed much since then. For me I have been very happy with these changes.
