Chip McCormick Trigger Groups/AR??????

I am looking into installing a Chip McCormick two stage trigger group in my AR. If you have or have had one of these triggers in your rifle how did you like it? Why/Not? Are they worth the money they ask for them. Did it improve your rifle and/or shooting? Did you install it yourself?(they appear to be "Drop in") Thanks for your time...........

JBoss......Fear No Fish/peace through superior firepower/The gun manufacturers are not making a dangerous product.
Bad parents are.