Hmmm... Should I care about the difference, or is it not worth worrying about? What if my printer is great but my monitor is a POS?
Remember that soft proofing is basically an editing tool: the goal is to allow you to see what your print will look like, but on your monitor. If some colors in your photo are out of gamut on the monitor, those colors cannot be emulated on the monitor and color will be inaccurate in those areas: they may print fine if they are in gamut on the printer but if they are out of gamut on your monitor, the soft proof itself won't represent what the print will look like. So basically either way (out of gamut for the printer or monitor), you have a problem. This is why I always drive home the point that you have to understand the limitations of soft proofing and always print to confirm. Terry and I may have different definitions of "reasonable quality" when it comes to monitors; I think 95% or more will not have an Eizo with a bigger-than-Adobe-RGB gamut as they would consider the price "unreasonable" unless they are a full time photo business.
You could use the new auto intent and not worry about it since that picks perceptual/RC based only on a gamut check of the printer and it ignores the monitor.
Regards,
Mike