I was torn between the CHVFZ, M5A99-FX Pro R2.0 and the Sabertooth 990FX R2.0 myself not that long ago. The 990FX R2.0 is essentialy the same board as the 990X Evo R2.0 except for the difference in PCI-E performance, which is only an issue really when running crossfire setups. I read lots of good things about all three boards, but ended up with the 990FX and pocketed the extra $80 difference to allocate elsewhere. What made my decision for me was thinking about the fact I am still running a Phenom processor myself, and regardless of how great the overclocking potential might be on the Crosshair board, the price difference would be better spent toward a FX8320/8350.
In the end, I actually built two systems with the 990FX R2.0 board as the foundation, and I'm extremely happy with both. Despite being at the disadvantage of only having a 6+2 power phasing configuration compared to the CHVFZ's 8+2 design, I still have reached overclock numbers that exceed anything I've seen the from Crosshair owners who are also running only air cooling. I have one Phenom X4 965 stable now at 4.55ghz.... the thought that I would be getting much more mileage out a different board, regardless of how great it might be designed, is doubtful at best. Like I said, the core design of the Evo is the same as the FX Pro, so I'd expect nothing less from it.
So, clearly I would vote for the 990X Evo R2.0 based on my own experience, and the concept of diminishing returns. If by chance you are truly looking at only the Crosshair V and not the revised V formula Z model, then it's a no-brainer.