I use the stock ALG ACT trigger that came in my BCM. This trigger uses the mil-spec geometry, which in my opinion is important for a serious use weapon, but is more consistent and smooth. The price is very reasonable as well if you're buying one aftermarket. I've tried the Geissele SSA and found it to be too light for my liking. That's just my opinion though. If you were building a target or hunting rifle I'd say the Geissele would be a good option.