I was surprised about the limited gains through COBB. Stage 1 is only 20 & 20 and stage 2 and 2+ require bolt on mods (downpipes and fmic I believe) to get more. For $100 more than COBB, ESS will provide greater HP and TQ without needing any other mods. But, COBB does offer some cool user features.
'08 Alpine white E92 M3 with DTC--Sold
'12 Alpine white E92 335 Xdrive with slush box
'07 Summit white Chevy 2500 HD Duramax/Allison
'12 Alpine white Z4 35is via EuroDelivery June 4th