Any opinions on this barrel?  What kind of groups can I expect out of it and is it in the Kreiger league?  Any info on vendors who supply a fully chambered drop in ready barrel?

The Kreiger uses cut rifling and the Douglas uses button rifling. Cut is more expensive than button and will usually last longer. As for accuracy, they can be just as accurate as the Kreiger but will usually not last as long. Then again the Douglas is cheaper than the Kreiger. Both can be excellent barrels. In fact, I have one of each. Both will shoot just as well as the other. However, that being said, it is very, very important that the chambering job be done correctly. You can have the best barrel in the world, but if the chambering job is bad it will be a POS. To do a good job the smith will need your bolt to set headspace correctly or you can buy a bolt with the barrel. John Holliger of White Oak Precision or Frank White of Compass Lake Engineering will do right by you. Do a web search for their addresses.

Don't forget Shilen or Pac-Nor(each around $300 for "drop-in"-never knew an AR barrel that drops in).  

223Rem is correct, there are many good shooting barrels out there. I also agree about the Pac-Nor and Shilen. My next one will be a Pac-Nor, probably next year. Hart also makes a good barrel.

Thanks to all for the responses.  I hadn't heard that cut rifling lasted longer than button.  Any thoughts on JP enterprises' barrels?  

Don't forget Les Baer Custom
They are offering both cut and button rifling.
Both in the mid to upper $300's

Certain military units found that Douglas could deliver barrels shooting as well or better than the others at half the cost.

The truth is that unless you are an outstanding competitive marksman, you will not outshoot any of the custom barrels in the field.

The chambering comments are well taken.  Almost all of the barrels mentioned, when properly installed will shoot well under 1 MOA, depending on the tuning, ammo, and shooter.