Originally Posted by
Huntingbear_grimbatol
As you said everything scales from weapon damage, you should aim to get the highest item level weapon which is 3.80 speed.
For instance the heroic 2handed axe from firelands is 3.60 speed with haste and mastery item level 391.
The normal version of ragnaros' weapon is 384 ilvl but is 3.80 speed (and has 31more str) and because of the slower swings (and secondary stats and str) it's better.
so to answer your question; the pvp wep would be slightly better just because of the increased pure damage it does.