Sorry, no allegations of hatred on this thread. But there are a few ACR threads on the go right now, with some hating.
My Giessele is a normal SSA. You just bend the spring slightly with a set of pliers, to match the stock trigger and it works perfect. They are about $175 to $200. Any AR trigger will work, except for the drop in Timney pack, style triggers.
In my opinion, the ACR is a unique rifle, and worth the price I paid. however I did not pay $4000 to buy a restricted model and then do the upgrades NR. If it was not as accurate I'd be less convinced.