i'd take the trade.
krejci is a 60 pt player. voracek is a 50ish pt player. the considerations are krejci plays with lucic and horton/seguin. voracek could play with giroux. both get prime pp time. most ppl are high on voracek because of his skill set (which he has) and the possiblitity he'll play with giroux. krejci is more consistent. I'd take the consitency over the gamble...