I had a Huey Pro that worked well for my monitor but I was still having problems with my printing (too dark and not enough magenta). I had tried various things to get my Epson Photo RX620 to print better with out having to buy another printer. You can find many reviews about the ColorMunki on the web but these are my personal opinions.
To start, the only problem I have had with the ColorMunki is that you only have 3 activations. I went to the X-rite support site yesterday and they say that you can uninstall the program and then put it on another computer to get by this. I guess that's not too bad.
For profiling a monitor, I fell in love with the advanced mode. It used the ColorMunki to tell you when your brightness and contrast are set correctly. Something that drove me nuts with the HueyPro is how it shows rings at different shades and you had to squint while adjusting the settings. It's wonderful not having to squint anymore and wondering if your close. It takes a bit longer to profile in advance mode than the HueyPro (it samples more colors and shades) but the profile that it builds is better.
As for printing (the main reason I bought it), it did wonders. First off, you should have some knowledge of color management and how to turn it off in your printer settings. Then you print a set of strips (it only prints them on 8.5" x 11" paper) and let them dry. You will then read the strips and it will come up with a second set of strips for you to print and read. After that, you are basically done and have a working profile. I have found that for some of the prints, I had to fine tune the profile. This is done by loading up a picture you want to print into the software and it comes up with a set of strips based on the colors in the print. You will then read the strips and your profile will update. I have had to do this a couple of times to get a the prints to come out even better (I'm a bit picky when it comes to how my prints look).
Overall, I have fallen in love with the ColorMunki. It does everything that it says and does it better then I had expected. It has spoiled me now and I hate not working on a calibrated system.