Not terribly worth it in my opinion. Yes they will be as good or better in turn one thanks to the +str than before, but afterwards they will die in droves before even hitting. Add to that the fact that you can't assault out of serpents anymore, which means you will be eating a ton of bolter fire before reaching those terminators.
Harlequins with a shadowseer now are pretty amazing. Expensive, but with their +3 to cover save their chances of reaching the enemy in one piece are pretty good and the new divination basic power+doom combo will make them wreck anything in combat.
Oh and the FAQ to lashwips forces banshees to roll off to see which effect governs and Enhance no longer helps...annoying.