I've been given the "task" to turn off the nitrogen in our reflow ovens. I am using the BTU, TRS series ovens, each with eight zones. Also, I have a couple of new BT Paragon ovens with 10 zones. We currently are running Qualitek 670 No Clean paste. We plan to switch to the Indium 92 Pin Probable paste later in the year (maybe Multicore - if I can pull it off). I run the air amp heaters in the TRS's at 280 C to keep em clean, which has worked for about 3 years now. The Paragons have the flux condenser option. My profiles are common ramp, soak, spike profiles (yeah, I know I don't need to soak) that are your common run-o-the-mill stuff.
My two biggest questions (to experienced players only! No arm-chair magazine readin' wanna be's) are one: Did you notice a difference in solder joint quality, and two: Did your oven PM increase due to flux residue?