Developer diaries are awesome
http://gaming.icrontic.com/article/steam-a-game-developers-dream/
Being in the Unstoppable Gorg’s beta is just pure joy. The game gets updated ever two days according to really close interaction between the developers and the testers. There’s even signed posters for the best feedback each week.
Granted, the game is not a first person shooter and there’s far more emphasis on the mechanics than on the technical aspect, but keep in mind that they used the same process for their Shattered Horizon as well, one of the heaviest and complex shooters today.