The newest, my 6.8PC AR15 dissipator. It's shorter than all the others, with a 16" barrel, but in 6.8, it's equal to the .30-30, with better flat line ballistics. It can take any scope I choose, and clamp on easily, or shoot iron sights. I can unload it more quickly, just pop the magazine and eject one round, unlike the manual actions which get jacked repeatedly - with the risk of a negligent discharge each time the round gets chambered. That also bangs up the ammo, and that's already known to make it more inaccurate.
It's light enough, and you really don't have to "clean" it like the older guns, which need constant repetitive maintenance during the year. They will rust speckle in a damp environment, cased or not, and require a good hosing down with a solvent and reoiling any time they leave the house. The tight fits harbor moisture that the AR shrugs off - anodized aluminum can go months in bad weather with just a wipedown. Steel simply cannot.
Drop it on a pile of rocks, the AR gets a scratch, the wood and iron guns get gouges in the stock wood, dings in thin metal, and a day later show rust in the iron where the flimsy bluing was scraped off.
As time goes by, I can change a part and improve it; as time goes by, the iron and wood guns fall further behind in technology, and deteriorate further, losing value. If I put them in a safe and never use them, they become completely useless, but they don't get any better.
I'm seriously considering selling off all the other long arms. They won't be any more valuable than right now, and aren't more accurate or reliable. They're just curios and relics in the long trail of evolving gun designs, as anachronistic as a phonograph or carburetor. People use those and claim them as a favorite, too, but they certainly are no longer "superior." Just quaint.