As Mzumbo said, Luck has ALOT to do with what you find. Also, time spent in the wasteland leads to better gear. The good stuff really starts rolling around the 2 day 12 hour mark, at least before the new patch came out. Finding crap and the occasional usable object is kinda the normal for 30 hours, even with 10 luck.
If you wanna be the very best like no one ever was, you're gonna need a dweller with max strength, endurance, and luck, and give him a lucky businesswear outfit which gives +7 to luck.
And yes, the game does continue to keep track of SPECIAL values over 10. I have a room of six people with 13 agility in a fully upgraded diner. The diner's timer is sitting somewhere around 39ish seconds, which is ridiculous for a fully upgraded triple room. I have a nuka cola plant resetting every 30 seconds too.
I sent my guy with 17 luck out into the wasteland for the first time just recently, I hope he finds good stuff!
Mzumbo, we can compare loot results to see if they might have tweaked it. 2 people does not a sample make, but its a start!