What I went through the whole color calibration process (years ago), I bought quite an expensive software and color meter from a company in Germany named basICColor. Results were good. But, the meter failed very quickly and the licensing of the software and activation was a pain in the ass when I would switch computers (main board failed on 2 computers, upgrades, etc.)
Being so problematic, I switched to buying a Spyder 2 and iColorDisplay. A cheaper solution and seems to be just as good. Also licensing and activation is no problem as I received a license file. Computer dead? Just a buy a new one and move on. I use no software that requires activation.
In both cases, I tested by giving my raw files to a lab and seeing how they processed and trying to see if the screen and the prints look right. One lab I caught making adjustments, which explained the differences... I would say I've got things under control.
Why change if it's working right now though?