I used to use GW Chaos Black spray primer, but it was expensive as hell and still came out somewhat shiny. The guy at Pegasus introduced me to "Board to Pieces" primer. it goes on a lot thinner, and is a very flat black with minimal sheen but is still a very smooth finish and makes my BT look sexy as hell. The only real "problem" i have with it is when i make a little mistake painting and have to go over it with chaos black it actually turns the chaos black into a shiney red spot

, though it only really shows on big flat areas on tanks. Other than that it is a very nice primer, is about $4-$5 less than GW primer, i've yet to see drips, and you do seem to get a lot out of it. i've done 5 boxes worth of AoBR Orks, 4000 pts of SM, and a CSM battleforce, and im down to like 1/3 of my 5th or 6th can? I can honestly say im never going back to GW primer again.