I took a buddy up in his aircraft, after he recently gained his Night VFR rating, and he wanted to try some 'under the hood training' for a possible upcoming IF course.
Within 30 minutes of some basic coordination exercises and a few Unusual Attitude recoveries, he called 'Time Out' and we landed.
He commented that he thought it might be easier, given his NVFR rating, but that he didn't appreciate just how demanding Instrument Flying was - and at that time he had no thinking about approaches to do, merely learning to correctly interpret the AI and other instruments in his scan.
End result - he's determined to get his Instrument Rating ASAP. The NVFR can provide overconfidence...