From what I've seen BMC and MS are M3Post member's favorite.
One point, EAS had clearance sale on AFE filters due to its fitment issue.
I have Dinan intake but I'm planning to try BMC with stock connector with Dinan C/F pipe as they have great reviews from forum members when my Dinan is ready to replace.
X5M: Dinan Exhaust | Dinan Suspension | Velos Tune | BMW Perfomance Splitter | Lux V4 | Euro Mirrors | H&R 12/25 mm Spacers | IND Cosmetic Package
PAST: 08 E90 M3 | 08 E92 335i | 03.5 E46 M3 | 99 E36 M3