Another cost advantage to the colormunki is that X-Rite does not license 3rd party software vendors to use the colormunki in their software (not a problem for HCFR with the Argyll drivers) so you have to use the more expensive Display 3 (OEM version) with commercial software.
Also interesting to note on the Argyll web page for the Display 3 / Colormunki that it notes the Colormunki takes a "noticeably longer time" to take measurements. There is a customer comment on amazon who compared the colormunki with the display 3 and says the colormunki is only 2x slower, not 5 times, quoting a full calibration with the software taking 5 minutes on the colormunki and 2.5 minutes on the display 3. Assuming the software calculation time is tiny compared to the meter sampling time, then these results should translate to HCFR pretty well. As the new Display 3 reads significantly faster than the older Display 2 LT, it would be reasonable to expect the colormunki to be about as fast as the old Display 2 LT. But the meter will read slower under 30 IRE (as does the older Display 2 LT).
To smokarz comment about trouble under 30 IRE, I have seen no evidence that the colormunki is less accurate and as the devices internally are almost identical (only firmware changes for the speed and ambient light support more than likely), its unlikely there is a difference. In fact the newer X-Rite meters are more accurate under 30 IRE according to the review on the Chromapure website. The amazon customer comment/review when comparing the D3 with the Colormunki showed identical results.
Another useful article gives a comparison between the colormunki/D3 and other meters, and shows these new x-rite meters to be very good, comparible to $1500+ meters, and a definite improvement over the older D2 meters.http://www.drycreekphoto.com/Learn/C...nHardware.html
Another good thread about the new x-rite meters: http://www.avsforum.com/avs-vb/showthread.php?t=1342422
So in conclusion, in comparison with the older Display 2 LT, the Colormunki Display will be more accurate (especially for lower IRE readings), drift less and have comparable speed for only a few bucks more than the old Display LT.