A few things:
The Battle Rifle is just a tad too weak. It's supposed to be more accurate and powerful than the magnum, but comparing the new BR to the Magnum in the Slayer playlist, I'm not sure I would want to pick up a BR if given the opportunity anymore. Maybe if the bullet magnetism was a bit more powerful, it would make it just enough better than the two people in an AR/Magnum starts arena game would definitely have an advantage. Also, please return the Team Arena starts to AR/Magnum after the tuning update. Even though the BR is weaker, having 8 of them on the map at the same time is rediculous.
The gunfighter magnum is tricky. If you can aim well at very short range, it is a great weapon with the 18 bullet magazine. Granted I like the Assault Rifle more, but I have had moderate success with it. Still make it a weapon to pick up, not standard starts.
The radar is awful. It's criminal to make walking at full speed undetectable. One of my favorite strategies, playing ring-around-the-rosie (hiding behind a tall, thin obstacle and running around so my enemy can't see me until my shield is up) is completely useless. Now it only takes sprinting and firing to alert the radar, and with the 18m range, someone can sprint at you from behind and spartan charge you before you know what hit you. Every Halo game has made walking set off the radar. Why change now?
The Railgun is great. The longer charge time makes it harder to keep the reticule on your opponent at close range, so it feels just about right at long range. I wouldn't mind it if the zoom brought you in a bit closer though.
The sword is a bit harder to use now, but with it only on two maps and the tendency for someone to get a spree with it doesn't really give me enough time to really get the feel for it. Honestly if the zoomed lunge was just a foot or two closer than it was before the test it'd be good.
Active Camo is definitely a more effective, and I have noticed a significant advantage of someone with it. I was able to sneak from immediately in front of someone to behind and beat them down much more often. It was much more difficult to kill a player with camo up close, because if they showed themselves it was hard to consistently aim at them. I'd say to keep it how it is in the test.
I have noticed that the DMR is less effective the closer it gets, but it is still good at long range. If I were to make one suggestion, it would to be lessen the ttk to make it equal to the BR (if it isn't already) because if I'm firing at long range my target can't usually get behind a wall before I can get the kill.
Any other weapons that I haven't mentioned that got tuned were either not available enough on the maps to get a feel for or not tuned enough that I can tell a difference.
One more thing about the sandbox in general. The overshield is great. You get two extra shields worth of protection, so it is very effective when you are only facing one or two people. However, it think that every single map that has an overshield should have at least one plasma weapon to pick up. Because as it is, someone with OS can walk up and kill anybody easily. But if they happened to attack someone with a plasma weapon, they can suddenly die quite quickly. Puts a bit more balancing on it. The power up itself is good. Don't change it. Just add more plasma weapons.
Thanks 343 for letting us help you tune the sandbox so hopefully we can all enjoy it!