I've always done BFB -> IR for two reasons.

1) You get the BFB right as you start ID, which is a PPS increase over using IR with ID, no matter which way you look at it
2) I love the increased chance of IR buffing my DFD, which I always land at the end of my opening burst. Both BFB + IR last until I use DFD.

When you go crit for 2k Full Thrust, followed by a 1.3k DFD, it gives me all kinds of giggles.