I've owned the Aguilar agro and used it a lot. Great with bass, keeps the lowend. I however own the darkglass b7k now. Its seriously an amazing piece of gear. it sounds different than the agro, different flavor but both are great IMO. I haven't tried the b3k but its the same overdrive sound as the b7k, except doesn't have the eq or di. Others might have more info to help.