Asus p8p67 pro vs asus p8p67

They have different PCI config:
Pro:
2 x PCIe 2.0 x16 (single at x16 or dual at x8/x8 mode)
1 x PCIe 2.0 x16 * [Black] (max. at x4 mode, compatible with PCIe x1 and x4 devices)
2 x PCIe 2.0 x1
2 x PCI
*The PCIe x16_3 slot shares bandwidth with PCIe x1_1 slot, PCIe x1_2 slot, USB3_34 and ESATA12. The PCIe x16_3 runs at x1 mode by default for system resource optimization.(PCIe x1_2 will be disabled.)
Multi-GPU Support Supports NVIDIA® Quad-GPU SLI™ Technology
Supports ATI® Quad-GPU CrossFireX™ Technology

Not-pro:
1 x PCIe 2.0 x16 (single at x16)
1 x PCIe 2.0 x16 * (max. at x4 mode [Black])
2 x PCIe 2.0 x1
3 x PCI
*The PCIEX16_2 slot shares bandwidth with the PCIEX1_1 slot, PCIEX1_2 slot and USB3_34 connector. The PCIEX16_2 runs at x1 mode by default for system resource optimization.
Multi-GPU Support Supports ATI® Quad-GPU CrossFireX™ Technology

Either there is a typo or only the pro supports SLI (multi-GPU for NVIDIA).
The Pro has a JMicron controller for two real E-Sata ports.
The Pro does not have a COM port.

Is it worth it? Not unless you need to use two NVIDIA cards, or attach ESata drives.
 
asus_p8p67_spec.jpg