I think autoloot is quite necessary for me, especially I go out hunting for enormous amounts of items for making a custom headgear, etc. I do not want to pick up 1000 feathers one by one lol. Secondly, there's a delay when it comes to monsters dropping the item, so that item is technically yours (if you do the most damage) regardless unless you lagged. Then, the surrounding players can get that card or whatever. Autoloot works in the same way I believe, but you wouldn't lose out to any lags. I still don't really see any cons with this personally.
I don't really care about Dual clienting--I can live without it anyways. It promotes "cheating" yet in other times, it's for convenience. There are good and bad points about having this available.