After having played both NA and EU (not just 'yeah, i topped XX scoreboard once'), i'd say that bec isn't a major issue, but is a tad too good against armor. The solution, in my opinion would be to either nerf pierce dmg slightly (would also nerf lolstabs etc.) or lower the bec swing dmg by 1-2 points or lower the bec speed by 1-2 points (dmg preferred).
This is no Biased EU/NA post since i have played on EU for 7-8 months and NA for 2 months, which should be enough to get a feeling of how things are on both continents, and therefore this is hopefully more 'objective' than the "EU sucks, bec is OP!" and "NA sucks and so does bec!" posts.