Lestat:

I am running 2x74 and believe me I have gone through this. Every bench I run show way lower scores including PCmark, Atto and hdtach. I have tested it on several platforms.

For example,
Atto runs 130-140 vs 100-110
pcmark hdd xp startup difference 2-3 points (which is quite a lot)
hdtach same 130 vs 110 (110 was using trick with PCI latency tool)

Ofcourse for general use it might be enough but since I am a bencher I think it is stupid to waste full potential

I compared NVraid and Intel raid vs slicion and promise PCI raid cards