Seems to be a hot or miss thing. I guess its mainly that the SGI kits are more hooked up to the engine management system and the like; plus its still on the first stage of development over here as compared to the venturi kits which have been around longer.

Thankfully my SGI kit is still doing well with nothing more needed then some fine-tuning in the start (same with my officemate... we both have similar rides. :D)