This is not scientific at all but hope it might be of some use.
lastMPServer="216.157.78.254:2502";
lastMPServerName="DayZ US Southeast 0-3 (Experimental/Unstable)";
started around 9pm Central US time on Sept 11, 2015
Twitch vod if needed: http://www.twitch.tv/kerbo_/v/15593452 (~2hr stream)
Observations
- Items dropped on ground were cleaned up a) I was 1 of 2 players on server b) I was more than 200m away from dropped items for 20-30 minutes c) A Taloon backpack mostly full of items was also cleaned up d) Barrels, garden plot, snare trap were still there e) A jacket and cooking pot with items inside were initially there when I returned but disappeared soon after, unknown time frame
- Fire was cleaned up a) Seemed to be timer related, about an hour b) I was within 100m of fire when it disappeared c) It had burned down to coals while I was away (time and distance from #1) d) I added more wood and re-ignited it about 5 minutes before it disappeared
- A lot of item ghosting occurs when moving items to/from barrels