Berk has good gains, and good sound. I almost bought Berk way back, before they started having issues with shipping, and people getting mismatched sets. Those issues have all been fixed now, but when I was in the market they were not my top choice.
Plus personally, I prefer the \_/ style of F.I. over the = style of Berk. I like to see those cans.
But Berk does have good sound, low cost, and good gains. The slight weight disadvantage really didn't bother me considering I have a hundred pound sub box sitting right on the rear axle anyways. Berk was my #2 option after F.I.