That version is also 1.55. I don't know how they compare exactly but I do know a few versions run much faster than others. I'm pretty sure they designed 2.00 to be about the same speed as 1.55 for modern hardware.
__________________ Project: Black and White i7 920 D0 | 3 x 2GB DDR3 | EVGA X58 SLI LE
XFX 4890 | Corsair HX750 | Corsair Obsidian |