I2O vs. Mass Storage Modes on Dell Perc Controller

[Questions]

I just installed 6.1 on a Dell PowerEdge 1850 and the RAID adapter was
initially set for Mass Storage mode.  I read that I2O mode is a better
mode, so I flipped it to I2O, and the machine booted fine.  For some
reason this confuses me.  I would assume that my changing the
emulation of the RAID Adapter would cause the machine to no longer
boot.  Am I wrong in this assumption and switching between emulation
modes should not affect booting?