It's a funny one the topic of cans-it's not just different brands, but also different configurations, length of the pipe work, diameter, they all affect how efficiently the engine expels the gasses. It is a shame there isn't a collection of dyno figures on varying styles and brands available to compare in one place on the site.

I'm aiming to get mine on the dyno soon, and i'm running a custom built set with k & n stage 1, dna stage 2 and PCV.

Will post results once obtained- but to get back to the original point, I'd agree with Pleidas and Gas up, best asses your needs and wants