ppl in this thread claimed pb was always best
others claimed zerk was always best
others said "pb pvm, zerk pvp", this is more correct, but still lacking explanations
the damage from the weapon (i.e. 15ed 3ar) is used in the charge, but not the smite
charge uses ar, and also the base damage from the weapon: smite does not
as others mentioned here: pb does not consume durability; also it's easier to reach the max ias bp using less restrictive gears
to be "properly" built with your grief in a pb, 30%-40% ias is the same: you will hit max ias easily, and the ias on grief is irrelevant
to be "properly" built with your grief in a zerker, you MUST HAVE 40% or you will be unable to hit the bp and still be geared properly
(my advice pertains to end-game pvp. for a 'proper' uber smiter no such thing. many trash gears set-ups which can do it easily..)
since grief +damage DOES affect smite, unless you have a 40/400 grief zerker, (crazy expensive..), then you are better off with even a 30-39/400 grief pb (much more affordable)
some pvp'rs would prefer, say, a 40-395 zerker over a 400 damage pb : this is because the ATTACK RANGE ADDITION MODIFIER is 2 with a zerk, and 1 with a pb
this MATTERS A LOT to a smiter in pvp, especially vs a whirlwind user who wants to stay riiiiight on the edge of you so his ww hits you but you can't reach him with smite
in the end, there are some situations where pb is superior, and others where grief is superior
about the added damage to charge it is small: switch to e death rune word or e death clever if you want crazy charge: have it in second hand sometimes: (using your alt account/alt pc barb for your 55 bo)
(& third for sorc chant for charge instead of just demon limb if you really want to go crazy)

there is little use factoring in of the additional damage to charge which comes from the 15% ed (and the irrelevant 3ar) : as someone already correctly mentioned, it isn't a big real at all
..the reason people said "it only matters if it's perfect"
is because people pay ungodly amounts of FG for 100% true perfect items