Hey Jon and RC,
Here is a write up I came across which has some really great info on a wide variety of triggers, and their differences and make up. It's a long read, but well worth it. After contacting many of the companies listed in the article, I have decided on the Timney for myself as well. I have used their triggers on many other weapons I own, and they have never let me down and they have superb customer service to boot.
The trigger PSE ships with their TAC-15i is completely non-adjustable due to the fact we have lawyers and sue happy people on this planet. They put a "safe" trigger in but if you want any accuracy at all, toss the factory trigger and get the Timney from Les here on this web-site. He has a great price and these triggers are mildly adjustable, extremely repeatable, and very crisp. Installation is a breeze and I suggest you take a look at Jon's install of his trigger as he has covered that very well.
Let us know how it goes and which trigger you go with and how it does for you.
Trigger/Fire Control Groups tested and evaluated - the "BEST" trigger for you??? - Page 1 - AR15.COM