Can't speak for the Brenspeed tunes but have always heard good things about the company in general and also their tunes. I just installed Bama's Street tune and also have their Performance and Race tunes in my handheld waiting for their turn. I have free tunes for life from American Muscle and Bama just joined froces with them so I got Bama's tunes for free. And American Muscle will update your tune free whenever you need one due to mods, and doesn't matter if you bought their mods or someone elses, or their own updates.
The Bama Street tune was noticeably stronger then stock and also better then my previous 93 octane steeda sct tune. You'll be happy either way. But not sure if Brenspeed provides free tunes if you bought mods from somewhere else? Ask them!
'07 GT/CS,Steeda CAI,93 Oct. Bama Tunes,FRPP 4:10's & K Springs,GT500 Struts/Shocks,Hurst Shift,SLP Loudmouths,Foose Rims(20x10+39mm/20x8.5+34mm),Nitto Invo 295/35&255/35,Eibach Camber Bolts,J&M Adj.Pan.Rod,Adj UCA&LCA's,AM Strut Tower Brace,Tru-Fiber GTS-3 Hood&Hood Shock,GT-R Headlight Splits,CDC Nozzle Reloc.,SHR Lwr Grille,Flush Louvers,Gas Cap&Medallion,UPR Ant. Del.,Hood Pin&Billet Strut Cvrs,Rad.Ext.Cvrs,Blk rotors/cals,Clear black turn signals,SRP Black Racing Pedals