Preamp phase invert button enabled or disabled during recording vocals with Omni ?

[chrisdee]

I wonder if there is a general practice reguarding this ?
Monitoring in the headphones there is a huge difference between recording with phase button enabled or disabled.

When disabled the monitored vocals sound more like when recorded, but when enabled the monitored vocals sounds much more like headvoice.
I think I prefer phase button enabled when recording because it sounds more like I hear vocals in my head (with zero latency).

The recorded vocals sound the same to me either way.