New Mac Pro - 6 or 12 cores for Logic?



I'm about to place an order for a new Mac Pro, to replace our previous Mac Pro.

Does anyone know if the 12 or the 6 core model is likely to deliver the best performance with Logic? The 6 core is clocked higher than the 12 core - 3.33GHz v 2.93GHz - and it's hard to get a handle on whether the additional cores are likely to compensate for the lower speed.

Does anyone who knows more than me about this stuff have a view? Is Logic even able to fully utilize all 12 cores?

On our current 8-core system I tend to see activity across 4 or 5 cores only, and the times we hit performance issues are when 1 particular core is being maxed out, even though others are idle or running at low load. That said, we're still using OS 10.5 so maybe load balancing is improved with 10.6.

Any help or advice very much appreciated.